From 87d9aad48759879bb4470349212798fa61c66160 Mon Sep 17 00:00:00 2001
From: AAA <35992542+TNTcraftHIM@users.noreply.github.com>
Date: Sun, 30 Aug 2026 18:38:36 +0800
Subject: [PATCH] fix: fix presentation and audited ownership invariants (#338)

* Fix presentation and frontend ownership invariants

* Fix audited backend ownership invariants
---
 deploy/release-app.sh                         |  29 ++
 src/client/components/living/Comic.tsx        |   1 -
 src/client/components/living/ComicTooltip.tsx |  32 +-
 src/client/components/living/Couch.tsx        |  18 +-
 src/client/components/living/Metrics.tsx      |   5 +-
 src/client/components/living/PawnDetail.tsx   |  13 +-
 src/client/components/living/RouteTree.tsx    |   9 +-
 .../components/living/ViewerOverview.tsx      |  19 +-
 .../components/living/participant-color.ts    |  10 +
 src/client/components/living/primitives.tsx   |   8 +-
 src/client/media/host-sfu-route.ts            |   4 +-
 src/client/media/video-frame-proof.ts         |  46 +-
 src/client/media/viewer-playback.ts           |  16 +
 src/client/media/viewer-presentation.ts       | 303 +++++-------
 src/client/media/viewer-quality-evidence.ts   |  41 +-
 src/client/media/viewer-sfu-route.ts          |   9 +-
 src/client/pages/HostPage.tsx                 | 302 ++++++------
 src/client/pages/ViewerPage.tsx               | 463 +++++++++++-------
 src/client/sfu/publisher.ts                   |   5 +
 src/client/styles.css                         | 145 ++++--
 src/client/ui/copy.ts                         |   6 +-
 src/client/ui/icons.tsx                       |   1 +
 src/client/webrtc/stats.ts                    |  13 +-
 src/client/webrtc/viewer-peer.ts              |   1 +
 src/server/hybrid-media-router.ts             |  26 +-
 src/server/room-route-controller.ts           |   9 +-
 src/server/room-store.ts                      |   5 +-
 tests/copy.test.ts                            |   4 +
 tests/hybrid-media-router.test.ts             |  87 ++++
 tests/living-components.test.ts               |  71 ++-
 tests/metric-cells.test.ts                    |  23 +-
 tests/release-app-recovery.sh                 | 132 +++++
 tests/release-app.test.ts                     |  24 +
 tests/room-route-controller.test.ts           |  46 ++
 tests/room-store.test.ts                      |  25 +-
 tests/route-transition.test.ts                |  87 ++++
 tests/route-tree.test.ts                      |  15 +
 tests/sfu-client.test.ts                      |  55 +++
 tests/video-frame-proof.test.ts               |  27 +-
 tests/viewer-peer-generation.test.ts          |  25 +
 tests/viewer-playback.test.ts                 |  21 +
 tests/viewer-presentation.test.ts             | 201 +++++++-
 tests/viewer-quality-evidence.test.ts         |  86 +++-
 43 files changed, 1791 insertions(+), 677 deletions(-)
 create mode 100644 src/client/components/living/participant-color.ts
 create mode 100644 src/client/media/viewer-playback.ts
 create mode 100644 tests/release-app-recovery.sh
 create mode 100644 tests/release-app.test.ts
 create mode 100644 tests/viewer-playback.test.ts

diff --git a/deploy/release-app.sh b/deploy/release-app.sh
index 950aa31..573f088 100644
--- a/deploy/release-app.sh
+++ b/deploy/release-app.sh
@@ -16,6 +16,7 @@ lock='/opt/screener/deploy.lock'
 public_origin="${SCREENER_PUBLIC_ORIGIN:-}"
 descriptor="$(realpath -e -- "$1")"
 stage=''
+release_owned=0
 cutover_started=0
 old_release=''
 
@@ -72,6 +73,29 @@ cleanup_stage() {
   rm -rf --one-file-system -- "$resolved"
 }
 
+cleanup_release() {
+  if [ "$release_owned" -ne 1 ] || { [ ! -e "$release" ] && [ ! -L "$release" ]; }; then
+    return
+  fi
+  if [ -n "$stage" ] && [ -e "$stage" ]; then
+    return
+  fi
+  local resolved parent base active
+  resolved="$(realpath -m -- "$release")"
+  parent="$(dirname -- "$resolved")"
+  base="$(basename -- "$resolved")"
+  active="$(readlink -f -- "$current" 2>/dev/null || true)"
+  if [ "$parent" != "$release_root" ] || [ "$base" != "$release_id" ] || \
+      [ "$active" = "$resolved" ] || [ -L "$release" ] || [ ! -d "$release" ]; then
+    printf 'refusing to remove unexpected release: %s\n' "$resolved" >&2
+    return 1
+  fi
+  if ! rm -rf --one-file-system -- "$resolved"; then
+    return 1
+  fi
+  release_owned=0
+}
+
 wait_for_health() {
   local body=''
   for _ in $(seq 1 120); do
@@ -102,6 +126,9 @@ recover() {
     systemctl start screener.service || ok=0
     wait_for_health || ok=0
   fi
+  if [ "$ok" -eq 1 ]; then
+    cleanup_release || ok=0
+  fi
   cleanup_stage
   printf 'deployment_failed=%s recovery_ok=%s current=%s active=%s\n' \
     "$code" "$ok" \
@@ -267,6 +294,7 @@ old_asset="$(OLD_RELEASE="$old_release" "$node" --input-type=module --eval '
   process.stdout.write(match[1]);
 ')"
 
+release_owned=1
 mv -- "$stage" "$release"
 stage=''
 test -d "$release"
@@ -310,6 +338,7 @@ fi
 test -z "$(journalctl -u screener.service --since "$cutover_since" -p warning --no-pager --output=cat)"
 
 asset_sha="$(sha256sum "$release/dist/client/$main_asset" | awk '{print $1}')"
+release_owned=0
 cutover_started=0
 trap - ERR HUP INT TERM EXIT
 printf 'deployment=ok revision=%s release=%s previous=%s artifact_sha=%s manifest_sha=%s asset=%s asset_sha=%s health_ms=%s firewall_sha=%s\n' \
diff --git a/src/client/components/living/Comic.tsx b/src/client/components/living/Comic.tsx
index adc11f8..eaebf71 100644
--- a/src/client/components/living/Comic.tsx
+++ b/src/client/components/living/Comic.tsx
@@ -899,7 +899,6 @@ ${rmBlock(
       <Frame x={164} w={152} theme={theme} />
       <rect x={30} y={22} width={70} height={44} rx={8} fill={TV_BODY} stroke={TV_EDGE} strokeWidth={2} />
       <rect x={36} y={28} width={58} height={30} rx={4} fill="#0a101c" />
-      <Moon x={72} y={43} k={0.55} />
       <path d="M65 66 c0 6 -4 8 -8 10" stroke={TV_EDGE} strokeWidth={2.5} fill="none" strokeLinecap="round" />
       <Plug x={57} y={76} className="vls-ho-plug" />
       <Floor x1={176} x2={304} y={78} />
diff --git a/src/client/components/living/ComicTooltip.tsx b/src/client/components/living/ComicTooltip.tsx
index edc36d4..f28df3c 100644
--- a/src/client/components/living/ComicTooltip.tsx
+++ b/src/client/components/living/ComicTooltip.tsx
@@ -11,9 +11,16 @@
 // Styling in styles.css under "comic tooltip" / "glyph draw-in". SSR-safe:
 // handlers only run in the browser.
 
-import { useEffect, useRef, useState, type ReactNode } from "react";
+import {
+  isValidElement,
+  useEffect,
+  useRef,
+  useState,
+  type ReactNode,
+} from "react";
 import { Comic, type ComicKind } from "./Comic";
 import { HintComic, isHintKind, type HintKind } from "./hints";
+import { isCopyKey, say } from "../../ui/copy";
 
 const LONG_PRESS_MS = 500;
 const TOUCH_HIDE_MS = 1500;
@@ -49,6 +56,23 @@ export function ComicTooltip({
   const [comicMounted, setComicMounted] = useState(false);
   const [liveAlign, setLiveAlign] = useState<Align | null>(null);
   const interactionOpen = hoverOpen || focusOpen || touchOpen;
+  const disabledTrigger =
+    isValidElement<{
+      disabled?: boolean;
+      "aria-label"?: string;
+      label?: string;
+      title?: string;
+    }>(children) &&
+    children.props.disabled === true;
+  const rawDisabledTriggerLabel = disabledTrigger
+    ? children.props["aria-label"] ??
+      children.props.label ??
+      children.props.title
+    : undefined;
+  const disabledTriggerLabel =
+    rawDisabledTriggerLabel && isCopyKey(rawDisabledTriggerLabel)
+      ? say(rawDisabledTriggerLabel)
+      : rawDisabledTriggerLabel;
 
   const mountComic = () => {
     if (comicUnmountTimer.current !== null) {
@@ -163,7 +187,9 @@ export function ComicTooltip({
   return (
     <span
       ref={wrapRef}
-      className={`lr-comic-tip-wrap${touchOpen ? " is-tip-open" : ""}`}
+      className={`lr-comic-tip-wrap${disabledTrigger ? " is-disabled-trigger" : ""}${hoverOpen ? " is-hover-open" : ""}${focusOpen ? " is-focus-open" : ""}${touchOpen ? " is-tip-open" : ""}`}
+      tabIndex={disabledTrigger ? 0 : undefined}
+      aria-label={disabledTriggerLabel}
       onPointerEnter={(event) => {
         pickAlign();
         if (event.pointerType !== "touch") {
@@ -250,9 +276,9 @@ export function ComicTooltip({
       }}
       onKeyDown={(event) => {
         if (event.key === "Escape") {
+          setHoverOpen(false);
           setTouchOpen(false);
           setFocusOpen(false);
-          (document.activeElement as HTMLElement | null)?.blur?.();
         } else if ((event.target as HTMLElement).matches(":focus-visible")) {
           mountComic();
           setFocusOpen(true);
diff --git a/src/client/components/living/Couch.tsx b/src/client/components/living/Couch.tsx
index 2b5ff77..964d14d 100644
--- a/src/client/components/living/Couch.tsx
+++ b/src/client/components/living/Couch.tsx
@@ -2,17 +2,7 @@
 // self carries the green pointer, the host wears a crown (topology only).
 import { Glyph } from "../../ui/icons";
 import { useCopy } from "../../ui/copy";
-
-const PAWN_COLORS = [
-  "var(--pawn-1)", "var(--pawn-2)", "var(--pawn-3)", "var(--pawn-4)",
-  "var(--pawn-5)", "var(--pawn-6)", "var(--pawn-7)", "var(--pawn-8)",
-];
-
-export function pawnColor(key: string): string {
-  let hash = 0;
-  for (const char of key) hash = (hash * 31 + char.charCodeAt(0)) | 0;
-  return PAWN_COLORS[Math.abs(hash) % PAWN_COLORS.length]!;
-}
+import { participantColor } from "./participant-color";
 
 export function PawnSvg({ color, crown }: { color: string; crown?: boolean }) {
   return (
@@ -80,7 +70,7 @@ export function Couch({
               : `${entry.name} · ${stateLabel}`;
             const inner = (
               <>
-                <PawnSvg color={pawnColor(entry.key)} />
+                <PawnSvg color={participantColor(entry.key)} />
                 <i
                   className={`lr-pawn-led${entry.connected ? "" : " is-wait"}`}
                   aria-hidden="true"
@@ -103,7 +93,7 @@ export function Couch({
                   key={entry.key}
                   className={className}
                   style={style}
-                  title={vis ? undefined : label}
+                  title={entry.name}
                   aria-label={label}
                 >
                   {inner}
@@ -116,7 +106,7 @@ export function Couch({
                 type="button"
                 className={className}
                 style={style}
-                title={vis ? undefined : label}
+                title={entry.name}
                 aria-label={label}
                 aria-pressed={selectedKey === entry.key}
                 onClick={() => onSelect?.(entry.key)}
diff --git a/src/client/components/living/Metrics.tsx b/src/client/components/living/Metrics.tsx
index 3c4c3e4..deec2ed 100644
--- a/src/client/components/living/Metrics.tsx
+++ b/src/client/components/living/Metrics.tsx
@@ -170,7 +170,10 @@ export function MetricCells({
     <span className="lr-meter-cell" title={vis ? undefined : title ?? t(label)} key={label + display}>
       <Glyph name={icon} size={16} />
       {vis ? (
-        <b>{display}</b>
+        <>
+          <b>{display}</b>
+          <span className="visually-hidden">{t(label)}</span>
+        </>
       ) : (
         <span className="lr-meter-text">
           <b>{display}</b>
diff --git a/src/client/components/living/PawnDetail.tsx b/src/client/components/living/PawnDetail.tsx
index 1e26c94..d5f8652 100644
--- a/src/client/components/living/PawnDetail.tsx
+++ b/src/client/components/living/PawnDetail.tsx
@@ -1,7 +1,8 @@
 // Per-viewer drill-down: name, route glyph, primary metrics, expandable
 // detailed metrics. Host sees every Viewer; a Viewer uses this only for relay
 // children because its own route already has the canonical details panel.
-import { PawnSvg, pawnColor } from "./Couch";
+import { PawnSvg } from "./Couch";
+import { participantColor } from "./participant-color";
 import { Glyph } from "../../ui/icons";
 import { ComicTooltip } from "./ComicTooltip";
 import { useCopy } from "../../ui/copy";
@@ -31,7 +32,13 @@ export function RouteGlyph({ route }: { route: "p2p" | "sfu" }) {
           <path d="M7 8h22" />
         </svg>
       )}
-      <b>{route === "sfu" ? "SFU" : "P2P"}</b>
+      {vis ? (
+        <span className="visually-hidden">
+          {t(route === "sfu" ? "state.route.sfu" : "state.route.p2p")}
+        </span>
+      ) : (
+        <b>{route === "sfu" ? "SFU" : "P2P"}</b>
+      )}
     </span>
   );
   return vis ? (
@@ -70,7 +77,7 @@ export function PawnDetail({
   return (
     <div className="lr-row is-sub lr-pawn-detail" role="group" aria-label={name}>
       <span className="lr-pawn-mini">
-        <PawnSvg color={pawnColor(pawnKey)} />
+        <PawnSvg color={participantColor(pawnKey)} />
       </span>
       {vis ? (
         <span className="visually-hidden">{name}</span>
diff --git a/src/client/components/living/RouteTree.tsx b/src/client/components/living/RouteTree.tsx
index 59b5d0a..16ca721 100644
--- a/src/client/components/living/RouteTree.tsx
+++ b/src/client/components/living/RouteTree.tsx
@@ -9,7 +9,8 @@ import {
   type TopologyBranch,
 } from "../../lib/participant-topology";
 import { useCopy } from "../../ui/copy";
-import { PawnSvg, pawnColor } from "./Couch";
+import { PawnSvg } from "./Couch";
+import { participantColor } from "./participant-color";
 import {
   topologyLayoutForViewport,
   type TopologyLayout,
@@ -326,7 +327,7 @@ export const RouteTree = memo(function RouteTree({
           className="lr-route-node is-host"
           transform={`translate(${centeredPawnX(hostPos.x, HOST_SCALE)}, ${hostPos.y - 20}) scale(${HOST_SCALE})`}
         >
-          <PawnSvg color="var(--couch)" crown />
+          <PawnSvg color={participantColor(hostPeerId ?? "host-pending")} crown />
         </g>
         <text
           className="lr-route-label is-host"
@@ -371,7 +372,7 @@ export const RouteTree = memo(function RouteTree({
               className={`lr-route-node${node.ready ? "" : " is-recovering"}${selected ? " is-selected" : ""}`}
               transform={`translate(${centeredPawnX(point.x, scale)}, ${point.y - 15}) scale(${scale})`}
             >
-              <PawnSvg color={pawnColor(node.key)} />
+              <PawnSvg color={participantColor(node.key)} />
               {selected ? (
                 <circle className="lr-route-selection" cx="20" cy="26" r="25" />
               ) : null}
@@ -389,7 +390,7 @@ export const RouteTree = memo(function RouteTree({
             transform={`translate(${centeredPawnX(point.x, ROOT_SCALE)}, ${point.y - 15}) scale(${ROOT_SCALE})`}
           >
             <PawnSvg
-              color={pawnColor(point.viewer.peerId)}
+              color={participantColor(point.viewer.peerId)}
             />
             {selectedPeerId === point.viewer.peerId ? (
               <circle className="lr-route-selection" cx="20" cy="26" r="25" />
diff --git a/src/client/components/living/ViewerOverview.tsx b/src/client/components/living/ViewerOverview.tsx
index 66b5cc4..adda082 100644
--- a/src/client/components/living/ViewerOverview.tsx
+++ b/src/client/components/living/ViewerOverview.tsx
@@ -2,7 +2,8 @@ import type { ConnectionMetrics } from "../../types";
 import { formatPacketLossPercent } from "../connection-details";
 import { Glyph, type GlyphName } from "../../ui/icons";
 import { useCopy, type CopyKey } from "../../ui/copy";
-import { PawnSvg, pawnColor } from "./Couch";
+import { PawnSvg } from "./Couch";
+import { participantColor } from "./participant-color";
 
 export interface ViewerOverviewEntry {
   key: string;
@@ -83,7 +84,7 @@ export function ViewerOverview({
               >
                 <span className="lr-viewer-overview-person" title={entry.statusLabel}>
                   <span className="lr-viewer-overview-pawn">
-                    <PawnSvg color={pawnColor(entry.key)} />
+                    <PawnSvg color={participantColor(entry.key)} />
                     <i className={entry.connected ? "" : "is-wait"} aria-hidden="true" />
                   </span>
                   <span className="lr-viewer-overview-person-copy">
@@ -102,7 +103,19 @@ export function ViewerOverview({
                     }
                     size={14}
                   />
-                  <b>{route}</b>
+                  {vis ? (
+                    <span className="visually-hidden">
+                      {t(
+                        entry.route === "sfu"
+                          ? "state.route.sfu"
+                          : entry.route === "p2p"
+                            ? "state.route.p2p"
+                            : "state.peer.connecting",
+                      )}
+                    </span>
+                  ) : (
+                    <b>{route}</b>
+                  )}
                 </span>
                 <span>{resolution}</span>
                 <span>{fps}</span>
diff --git a/src/client/components/living/participant-color.ts b/src/client/components/living/participant-color.ts
new file mode 100644
index 0000000..311212e
--- /dev/null
+++ b/src/client/components/living/participant-color.ts
@@ -0,0 +1,10 @@
+const PARTICIPANT_COLORS = [
+  "var(--pawn-1)", "var(--pawn-2)", "var(--pawn-3)", "var(--pawn-4)",
+  "var(--pawn-5)", "var(--pawn-6)", "var(--pawn-7)", "var(--pawn-8)",
+];
+
+export function participantColor(identity: string): string {
+  let hash = 0;
+  for (const char of identity) hash = (hash * 31 + char.charCodeAt(0)) | 0;
+  return PARTICIPANT_COLORS[Math.abs(hash) % PARTICIPANT_COLORS.length]!;
+}
diff --git a/src/client/components/living/primitives.tsx b/src/client/components/living/primitives.tsx
index 6e7e3dd..2983b22 100644
--- a/src/client/components/living/primitives.tsx
+++ b/src/client/components/living/primitives.tsx
@@ -2,6 +2,7 @@
 // title/aria; text modes add a visible caption from the same catalog.
 import type { CSSProperties, MouseEvent, ReactNode } from "react";
 import { ComicTooltip } from "./ComicTooltip";
+import { participantColor } from "./participant-color";
 import type { ComicKind } from "./Comic";
 import type { HintKind } from "./hints";
 import { Glyph, type GlyphName } from "../../ui/icons";
@@ -281,11 +282,14 @@ export function SwitchItem({
   );
 }
 
-export function NameTag({ name }: { name: string }) {
+export function NameTag({ name, identity }: { name: string; identity: string }) {
   const { t, vis } = useCopy();
   return (
     <span className="lr-name-tag" title={vis ? undefined : t("host.name")}>
-      <i aria-hidden="true" />
+      <i
+        aria-hidden="true"
+        style={{ backgroundColor: participantColor(identity) }}
+      />
       <span>{name}</span>
     </span>
   );
diff --git a/src/client/media/host-sfu-route.ts b/src/client/media/host-sfu-route.ts
index 75e2542..fd4176a 100644
--- a/src/client/media/host-sfu-route.ts
+++ b/src/client/media/host-sfu-route.ts
@@ -197,8 +197,7 @@ export class HostSfuRoute {
   ): Promise<void> {
     if (
       this.closed ||
-      !this.route.acceptsConfig(message.revision) ||
-      this.paused
+      !this.route.acceptsConfig(message.revision)
     ) {
       return;
     }
@@ -516,6 +515,7 @@ export class HostSfuRoute {
         await disconnectPublisher(slot.publisher);
         return false;
       }
+      slot.publisher.setPaused(this.paused);
       if (this.pending !== slot || !this.ownsPublisherSlot(slot)) {
         await disconnectPublisher(slot.publisher);
         return false;
diff --git a/src/client/media/video-frame-proof.ts b/src/client/media/video-frame-proof.ts
index 82c650a..36f58d6 100644
--- a/src/client/media/video-frame-proof.ts
+++ b/src/client/media/video-frame-proof.ts
@@ -1,8 +1,11 @@
-type VideoWithFrameCallback = HTMLVideoElement & {
+interface OptionalVideoFrameCallbacks {
   requestVideoFrameCallback?: (
     callback: (now: DOMHighResTimeStamp) => void,
   ) => number;
   cancelVideoFrameCallback?: (handle: number) => void;
+}
+
+type VideoWithFrameCallback = HTMLVideoElement & {
   webkitDecodedFrameCount?: number;
 };
 
@@ -21,6 +24,9 @@ export function observeCompositedVideoFrame(
   onFrame: () => void,
 ): () => void {
   const target = video as VideoWithFrameCallback;
+  const frameCallbacks = video as unknown as OptionalVideoFrameCallbacks;
+  const requestVideoFrameCallback =
+    frameCallbacks.requestVideoFrameCallback?.bind(video);
   let active = true;
   let frameCallbackHandle: number | null = null;
   const fallbackEvents = ["loadeddata", "timeupdate", "playing"] as const;
@@ -51,25 +57,43 @@ export function observeCompositedVideoFrame(
     }
   }
 
-  function finish(): void {
-    if (
-      !active ||
-      video.srcObject !== expectedStream ||
-      video.readyState < 2
-    ) {
-      return;
+  function finish(): boolean {
+    if (!active) {
+      return true;
+    }
+    if (video.srcObject !== expectedStream) {
+      active = false;
+      removeFallbackListeners();
+      return true;
+    }
+    if (video.readyState < 2) {
+      return false;
     }
     active = false;
     removeFallbackListeners();
     onFrame();
+    return true;
   }
 
-  if (target.requestVideoFrameCallback) {
-    frameCallbackHandle = target.requestVideoFrameCallback(() => finish());
+  function requestNextFrame(): void {
+    frameCallbackHandle =
+      requestVideoFrameCallback?.(() => {
+        frameCallbackHandle = null;
+        if (!finish()) {
+          requestNextFrame();
+        }
+      }) ?? null;
+  }
+
+  if (requestVideoFrameCallback) {
+    requestNextFrame();
     return () => {
       active = false;
       if (frameCallbackHandle !== null) {
-        target.cancelVideoFrameCallback?.(frameCallbackHandle);
+        frameCallbacks.cancelVideoFrameCallback?.call(
+          video,
+          frameCallbackHandle,
+        );
       }
     };
   }
diff --git a/src/client/media/viewer-playback.ts b/src/client/media/viewer-playback.ts
new file mode 100644
index 0000000..23860f6
--- /dev/null
+++ b/src/client/media/viewer-playback.ts
@@ -0,0 +1,16 @@
+type ViewerPlaybackElement = Pick<HTMLVideoElement, "srcObject" | "pause">;
+
+export function prepareViewerPlayback(
+  video: ViewerPlaybackElement,
+  stream: MediaStream,
+  paused: boolean,
+): boolean {
+  if (video.srcObject !== stream) {
+    video.srcObject = stream;
+  }
+  if (paused) {
+    video.pause();
+    return false;
+  }
+  return true;
+}
diff --git a/src/client/media/viewer-presentation.ts b/src/client/media/viewer-presentation.ts
index 8d14cce..438ce26 100644
--- a/src/client/media/viewer-presentation.ts
+++ b/src/client/media/viewer-presentation.ts
@@ -71,11 +71,13 @@ interface ViewerRouteStatusFact {
 interface ViewerMediaFact {
   generation: number;
   boundAtRevision: number;
+  proofEpoch: number;
   framePresented: boolean;
 }
 
 export interface ViewerPresentationState {
   access: "checking" | "ready" | "denied";
+  accessFailure: ViewerFailureCode | null;
   signal: SignalConnectionState;
   host: ViewerHostState;
   revision: number | null;
@@ -90,7 +92,8 @@ export interface ViewerPresentationState {
   media: ViewerMediaFact | null;
   retainedFrame: boolean;
   autoplayBlockedGeneration: number | null;
-  failure: ViewerFailureCode | null;
+  playbackFailedGeneration: number | null;
+  runtimeFailure: "SERVER_ERROR" | null;
 }
 
 export type ViewerPresentationAction =
@@ -118,19 +121,20 @@ export type ViewerPresentationAction =
       connection: ViewerPresentationState["connection"];
     }
   | { type: "media-bound"; generation: number; revision: number }
-  | { type: "frame-presented"; generation: number; revision: number }
+  | {
+      type: "frame-presented";
+      generation: number;
+      proofEpoch: number;
+      revision: number;
+    }
   | { type: "frame-proof-reset"; generation: number; revision: number }
+  | { type: "frame-proof-rearm"; generation: number }
   | { type: "autoplay-blocked"; generation: number; revision: number }
   | { type: "autoplay-cleared"; generation: number }
   | { type: "playback-failed"; generation: number; revision: number }
-  | { type: "media-invalidated"; revision: number }
   | { type: "media-cleared" }
   | { type: "sharing-stopped" }
-  | {
-      type: "failure";
-      failure: ViewerFailureCode | null;
-      revision?: number;
-    };
+  | { type: "server-error" };
 
 export interface ViewerPresentation {
   stage: ViewerStage;
@@ -148,6 +152,7 @@ export interface ViewerPresentation {
 
 export const INITIAL_VIEWER_PRESENTATION_STATE: ViewerPresentationState = {
   access: "checking",
+  accessFailure: null,
   signal: "offline",
   host: "unknown",
   revision: null,
@@ -157,7 +162,8 @@ export const INITIAL_VIEWER_PRESENTATION_STATE: ViewerPresentationState = {
   media: null,
   retainedFrame: false,
   autoplayBlockedGeneration: null,
-  failure: null,
+  playbackFailedGeneration: null,
+  runtimeFailure: null,
 };
 
 export function reduceViewerPresentation(
@@ -169,35 +175,22 @@ export function reduceViewerPresentation(
       return {
         ...state,
         access: action.access,
-        failure:
+        accessFailure:
           action.failure !== undefined
             ? action.failure
             : action.access === "ready"
               ? null
-              : state.failure,
+              : state.accessFailure,
+        runtimeFailure:
+          action.access === "ready" ? null : state.runtimeFailure,
       };
     case "signal":
-      return {
-        ...state,
-        signal: action.signal,
-        failure:
-          action.signal === "connected" &&
-          (state.failure === "SIGNAL_TERMINATED" ||
-            state.failure === "SESSION_REPLACED")
-            ? null
-            : state.failure,
-      };
+      return { ...state, signal: action.signal };
     case "host": {
-      const failure =
-        action.host === "offline"
-          ? "HOST_OFFLINE"
-          : action.host === "stopped"
-            ? "HOST_STOPPED"
-            : state.failure === "HOST_OFFLINE" ||
-                state.failure === "HOST_STOPPED"
-              ? null
-              : state.failure;
-      return { ...state, host: action.host, failure };
+      if (action.host === "offline" && state.host === "stopped") {
+        return state;
+      }
+      return { ...state, host: action.host };
     }
     case "route": {
       if (state.revision !== null && action.revision < state.revision) {
@@ -206,9 +199,7 @@ export function reduceViewerPresentation(
       const revisionChanged = state.revision !== action.revision;
       const committedRoute = action.phase === "active" && action.kind !== "none";
       const reactivatingTerminalRoute =
-        committedRoute &&
-        (state.routeStatus?.state === "failed" ||
-          state.failure === "ROUTE_EXHAUSTED");
+        committedRoute && state.routeStatus?.state === "failed";
       return {
         ...state,
         revision: action.revision,
@@ -230,10 +221,6 @@ export function reduceViewerPresentation(
               ? "idle"
               : "connecting"
             : state.connection,
-        failure:
-          committedRoute && state.failure === "ROUTE_EXHAUSTED"
-            ? null
-            : state.failure,
       };
     }
     case "route-status": {
@@ -245,7 +232,11 @@ export function reduceViewerPresentation(
       const currentFrame = hasCurrentFrame(state);
       const currentMedia =
         terminal && state.media
-          ? { ...state.media, framePresented: false }
+          ? {
+              ...state.media,
+              proofEpoch: state.media.proofEpoch + 1,
+              framePresented: false,
+            }
           : state.media;
       return {
         ...state,
@@ -264,17 +255,7 @@ export function reduceViewerPresentation(
           ? null
           : state.autoplayBlockedGeneration,
         retainedFrame:
-          state.retainedFrame ||
-          ((revisionChanged || terminal) && currentFrame),
-        failure:
-          action.state === "failed"
-            ? "ROUTE_EXHAUSTED"
-            : revisionChanged &&
-                (state.failure === "ROUTE_EXHAUSTED" ||
-                  state.failure === "AUTOPLAY_BLOCKED" ||
-                  state.failure === "PLAYBACK_FAILED")
-              ? null
-              : state.failure,
+          state.retainedFrame || (terminal && currentFrame),
       };
     }
     case "connection":
@@ -290,9 +271,7 @@ export function reduceViewerPresentation(
       if (
         (state.media && action.generation <= state.media.generation) ||
         (state.routeStatus?.revision === action.revision &&
-          state.routeStatus.state === "failed") ||
-        (state.revision === action.revision &&
-          state.failure === "ROUTE_EXHAUSTED")
+          state.routeStatus.state === "failed")
       ) {
         return state;
       }
@@ -301,24 +280,20 @@ export function reduceViewerPresentation(
         media: {
           generation: action.generation,
           boundAtRevision: action.revision,
+          proofEpoch: 0,
           framePresented: false,
         },
         retainedFrame: state.retainedFrame || hasCurrentFrame(state),
         autoplayBlockedGeneration: null,
-        failure:
-          state.failure === "AUTOPLAY_BLOCKED" ||
-          state.failure === "PLAYBACK_FAILED" ||
-          state.failure === "ROUTE_EXHAUSTED"
-            ? null
-            : state.failure,
+        playbackFailedGeneration: null,
       };
     }
     case "frame-presented":
       if (
         !state.media ||
         state.media.generation !== action.generation ||
-        state.routeStatus?.state === "failed" ||
-        state.failure === "ROUTE_EXHAUSTED"
+        state.media.proofEpoch !== action.proofEpoch ||
+        state.media.framePresented
       ) {
         return state;
       }
@@ -328,21 +303,31 @@ export function reduceViewerPresentation(
         media: { ...state.media, framePresented: true },
         retainedFrame: false,
         routeStatus: null,
-        failure:
-          state.failure === "PLAYBACK_FAILED" ? null : state.failure,
+        playbackFailedGeneration: null,
       };
     case "frame-proof-reset":
-      if (
-        !state.media ||
-        state.media.generation !== action.generation ||
-        !state.media.framePresented
-      ) {
+      if (!state.media || state.media.generation !== action.generation) {
         return state;
       }
       return {
         ...state,
-        media: { ...state.media, framePresented: false },
-        retainedFrame: true,
+        media: {
+          ...state.media,
+          proofEpoch: state.media.proofEpoch + 1,
+          framePresented: false,
+        },
+        retainedFrame: state.retainedFrame || state.media.framePresented,
+      };
+    case "frame-proof-rearm":
+      if (!state.media || state.media.generation !== action.generation) {
+        return state;
+      }
+      return {
+        ...state,
+        media: {
+          ...state.media,
+          proofEpoch: state.media.proofEpoch + 1,
+        },
       };
     case "autoplay-blocked":
       if (
@@ -354,7 +339,6 @@ export function reduceViewerPresentation(
       return {
         ...state,
         autoplayBlockedGeneration: action.generation,
-        failure: "AUTOPLAY_BLOCKED",
       };
     case "autoplay-cleared":
       if (state.autoplayBlockedGeneration !== action.generation) {
@@ -363,8 +347,6 @@ export function reduceViewerPresentation(
       return {
         ...state,
         autoplayBlockedGeneration: null,
-        failure:
-          state.failure === "AUTOPLAY_BLOCKED" ? null : state.failure,
       };
     case "playback-failed":
       if (
@@ -373,23 +355,14 @@ export function reduceViewerPresentation(
       ) {
         return state;
       }
-      return { ...state, failure: "PLAYBACK_FAILED" };
-    case "media-invalidated":
-      if (state.revision !== action.revision) {
-        return state;
-      }
-      return {
-        ...state,
-        media: null,
-        retainedFrame: state.retainedFrame || hasCurrentFrame(state),
-        autoplayBlockedGeneration: null,
-      };
+      return { ...state, playbackFailedGeneration: action.generation };
     case "media-cleared":
       return {
         ...state,
         media: null,
         retainedFrame: false,
         autoplayBlockedGeneration: null,
+        playbackFailedGeneration: null,
       };
     case "sharing-stopped":
       return {
@@ -402,36 +375,11 @@ export function reduceViewerPresentation(
         media: null,
         retainedFrame: false,
         autoplayBlockedGeneration: null,
-        failure: "HOST_STOPPED",
-      };
-    case "failure":
-      if (
-        action.revision !== undefined &&
-        state.revision !== null &&
-        action.revision < state.revision
-      ) {
-        return state;
-      }
-      const terminalRoute = action.failure === "ROUTE_EXHAUSTED";
-      const terminalMedia =
-        terminalRoute && state.media
-          ? { ...state.media, framePresented: false }
-          : state.media;
-      return {
-        ...state,
-        revision:
-          action.revision === undefined
-            ? state.revision
-            : Math.max(state.revision ?? 0, action.revision),
-        media: terminalMedia,
-        connection: terminalRoute ? "failed" : state.connection,
-        retainedFrame:
-          state.retainedFrame || (terminalRoute && hasCurrentFrame(state)),
-        autoplayBlockedGeneration: terminalRoute
-          ? null
-          : state.autoplayBlockedGeneration,
-        failure: action.failure,
+        playbackFailedGeneration: null,
+        runtimeFailure: null,
       };
+    case "server-error":
+      return { ...state, runtimeFailure: "SERVER_ERROR" };
   }
 }
 
@@ -446,7 +394,7 @@ export function deriveViewerPresentation(
     return presentation("joining", "viewer.msg.joining", "blocking", state);
   }
   if (state.access === "denied") {
-    switch (state.failure) {
+    switch (state.accessFailure) {
       case "ROOM_NOT_FOUND":
         return presentation(
           "room-not-found",
@@ -519,7 +467,13 @@ export function deriveViewerPresentation(
     state.autoplayBlockedGeneration === state.media.generation &&
     state.connection === "connected"
   ) {
-    return presentation("needs-play", "viewer.msg.needsPlay", "status", state);
+    return presentation(
+      "needs-play",
+      "viewer.msg.needsPlay",
+      "status",
+      state,
+      "AUTOPLAY_BLOCKED",
+    );
   }
 
   if (currentFrame) {
@@ -542,6 +496,7 @@ export function deriveViewerPresentation(
         : mediaRecovering
           ? "viewer.notice.mediaRecovering"
           : null,
+      failureCode: state.host === "offline" ? "HOST_OFFLINE" : null,
     };
   }
 
@@ -551,66 +506,50 @@ export function deriveViewerPresentation(
       "viewer.msg.routeFailed",
       frameOverlay,
       state,
+      "ROUTE_EXHAUSTED",
     );
   }
 
-  switch (state.failure) {
-    case "ROUTE_EXHAUSTED":
-      return presentation(
-        "route-failed",
-        "viewer.msg.routeFailed",
-        frameOverlay,
-        state,
-      );
-    case "PLAYBACK_FAILED":
-      return presentation(
-        "playback-failed",
-        "viewer.msg.playbackFailed",
-        frameOverlay,
-        state,
-      );
-    case "SERVER_ERROR":
-      return presentation(
-        "server-error",
-        "viewer.msg.serverError",
-        frameOverlay,
-        state,
-      );
-    case "STALE_CLIENT":
-      return presentation(
-        "stale-client",
-        "viewer.msg.stale",
-        frameOverlay,
-        state,
-      );
-    case "SESSION_REPLACED":
-      return presentation(
-        "session-replaced",
-        "viewer.msg.sessionReplaced",
-        frameOverlay,
-        state,
-      );
-    case "SIGNAL_TERMINATED":
-      return presentation(
-        "signal-terminated",
-        "viewer.msg.signalTerminated",
-        frameOverlay,
-        state,
-      );
-    case "HOST_OFFLINE":
-      return presentation(
-        "host-offline",
-        "viewer.msg.hostOffline",
-        frameOverlay,
-        state,
-      );
-    case "HOST_STOPPED":
-      return presentation(
-        "waiting-host",
-        "viewer.msg.waitingHost",
-        frameOverlay,
-        state,
-      );
+  if (
+    state.media &&
+    state.playbackFailedGeneration === state.media.generation
+  ) {
+    return presentation(
+      "playback-failed",
+      "viewer.msg.playbackFailed",
+      frameOverlay,
+      state,
+      "PLAYBACK_FAILED",
+    );
+  }
+
+  if (state.runtimeFailure === "SERVER_ERROR") {
+    return presentation(
+      "server-error",
+      "viewer.msg.serverError",
+      frameOverlay,
+      state,
+      "SERVER_ERROR",
+    );
+  }
+
+  if (state.host === "stopped" || state.host === "unknown") {
+    return presentation(
+      "waiting-host",
+      "viewer.msg.waitingHost",
+      frameOverlay,
+      state,
+      state.host === "stopped" ? "HOST_STOPPED" : null,
+    );
+  }
+  if (state.host === "offline") {
+    return presentation(
+      "host-offline",
+      "viewer.msg.hostOffline",
+      frameOverlay,
+      state,
+      "HOST_OFFLINE",
+    );
   }
 
   if (state.routeStatus?.state === "waiting") {
@@ -649,22 +588,6 @@ export function deriveViewerPresentation(
       state,
     );
   }
-  if (state.host === "stopped" || state.host === "unknown") {
-    return presentation(
-      "waiting-host",
-      "viewer.msg.waitingHost",
-      frameOverlay,
-      state,
-    );
-  }
-  if (state.host === "offline") {
-    return presentation(
-      "host-offline",
-      "viewer.msg.hostOffline",
-      frameOverlay,
-      state,
-    );
-  }
   if (state.route?.kind === "p2p") {
     return presentation(
       "preparing-p2p",
@@ -720,6 +643,8 @@ function presentation(
   messageKey: ViewerMessageKey,
   overlay: ViewerPresentation["overlay"],
   state: ViewerPresentationState,
+  failureCode: ViewerFailureCode | null =
+    state.access === "denied" ? state.accessFailure : null,
 ): ViewerPresentation {
   return {
     stage,
@@ -728,7 +653,7 @@ function presentation(
     overlay,
     hasCurrentFrame: hasCurrentFrame(state),
     hasRetainedFrame: state.retainedFrame,
-    failureCode: state.failure,
+    failureCode,
     connectionState:
       state.connection === "idle"
         ? state.host === "online" || state.host === "paused"
diff --git a/src/client/media/viewer-quality-evidence.ts b/src/client/media/viewer-quality-evidence.ts
index 2ac4a87..29ba924 100644
--- a/src/client/media/viewer-quality-evidence.ts
+++ b/src/client/media/viewer-quality-evidence.ts
@@ -246,25 +246,21 @@ export class ViewerQualityEvidenceReporter {
       return false;
     }
     this.lastSampleTimestampMs = sampleTimestampMs;
-    if (!presentationEligible) {
-      if (this.presentationEligible) {
-        this.invalidatePresentation();
-      }
-      return false;
-    }
-    if (!this.presentationEligible) {
-      this.presentationEligible = true;
-      this.baselinePending = true;
-    }
     const decodedProgress =
       metrics.intervalFramesDecoded !== null &&
       metrics.intervalFramesDecoded > 0;
-    if (!decodedProgress) {
-      return false;
+    let routingEligible = presentationEligible && decodedProgress;
+    if (!routingEligible) {
+      if (this.presentationEligible) {
+        this.invalidatePresentation();
+      }
+    } else if (!this.presentationEligible) {
+      this.presentationEligible = true;
+      this.baselinePending = true;
     }
-    if (this.baselinePending) {
+    if (routingEligible && this.baselinePending) {
       this.baselinePending = false;
-      return false;
+      routingEligible = false;
     }
     if (this.sequence > Number.MAX_SAFE_INTEGER) {
       return false;
@@ -286,7 +282,7 @@ export class ViewerQualityEvidenceReporter {
         presentationEpoch: this.presentationEpoch,
       },
       sequence: this.sequence,
-      ...window,
+      ...(routingEligible ? window : diagnosticOnlyWindow(window)),
     };
     const parsed = viewerQualityEvidenceMessageSchema.safeParse(message);
     if (
@@ -326,6 +322,21 @@ export class ViewerQualityEvidenceReporter {
   }
 }
 
+function diagnosticOnlyWindow(
+  window: ViewerQualityEvidenceWindow,
+): ViewerQualityEvidenceWindow {
+  return {
+    ...window,
+    metrics: {
+      ...window.metrics,
+      freezeCountDelta: null,
+      freezeDurationMsDelta: null,
+      pauseCountDelta: null,
+      pauseDurationMsDelta: null,
+    },
+  };
+}
+
 function sameViewerQualityEvidenceIdentity(
   previous: ViewerQualityEvidence,
   next: ViewerQualityEvidence,
diff --git a/src/client/media/viewer-sfu-route.ts b/src/client/media/viewer-sfu-route.ts
index 7c67c1c..bd92963 100644
--- a/src/client/media/viewer-sfu-route.ts
+++ b/src/client/media/viewer-sfu-route.ts
@@ -271,6 +271,12 @@ export class ViewerSfuRoute {
     }
     if (paused) {
       this.discardPending();
+      return;
+    }
+    for (const slot of new Set([this.active, this.pending])) {
+      if (slot?.activated && !slot.failed) {
+        slot.subscriber.armDecodedFrameProof();
+      }
     }
   }
 
@@ -406,8 +412,7 @@ export class ViewerSfuRoute {
   ): Promise<void> {
     if (
       this.closed ||
-      !this.route.acceptsConfig(message.revision) ||
-      this.paused
+      !this.route.acceptsConfig(message.revision)
     ) {
       return;
     }
diff --git a/src/client/pages/HostPage.tsx b/src/client/pages/HostPage.tsx
index 1d0f05a..235afab 100644
--- a/src/client/pages/HostPage.tsx
+++ b/src/client/pages/HostPage.tsx
@@ -397,9 +397,7 @@ export function HostPage({ onAuthorizationRequired }: HostPageProps = {}) {
     "access" | "replacement" | "sharing" | null
   >(null);
   const roomMutating = roomMutation !== null;
-  const [viewerPasswordEnabled, setViewerPasswordEnabled] = useState(
-    creationProfile.roomPassword !== null,
-  );
+  const [viewerPasswordEnabled, setViewerPasswordEnabled] = useState(false);
   useEffect(() => {
     creationProfileRef.current = creationProfile;
   }, [creationProfile]);
@@ -2265,14 +2263,14 @@ export function HostPage({ onAuthorizationRequired }: HostPageProps = {}) {
   }
 
   async function changeCodeEntryPolicy(policy: CodeEntryPolicy): Promise<void> {
-    if (policy === activeCodeEntryPolicy) {
-      setNotice(null);
-      return;
-    }
     const activeRoom = roomRef.current;
     if (!activeRoom) {
       return;
     }
+    if (activeRoom.codeEntryPolicy === policy) {
+      setNotice(null);
+      return;
+    }
     const mutation = beginRoomMutation("access");
     if (!mutation) {
       return;
@@ -2448,8 +2446,7 @@ export function HostPage({ onAuthorizationRequired }: HostPageProps = {}) {
     window.location.assign(route);
   }
 
-  const activeCodeEntryPolicy =
-    room?.codeEntryPolicy ?? creationProfile.codeEntryPolicy;
+  const activeCodeEntryPolicy = room?.codeEntryPolicy ?? null;
   const hostPeerId = hostPresence?.peerId ?? hostPeerIdRef.current;
 
   const couchEntries: CouchEntry[] = viewers.map((viewer) => {
@@ -2825,32 +2822,111 @@ export function HostPage({ onAuthorizationRequired }: HostPageProps = {}) {
         </div>
 
         <div className="lr-deck">
-          {showConnectionDetails && viewerOverviewEntries.length > 0 ? (
-            <ViewerOverview
-              entries={viewerOverviewEntries}
-              selectedKey={selectedPawn}
-              onSelect={(peerId) =>
-                setSelectedPawn((current) =>
-                  current === peerId ? null : peerId,
-                )
-              }
-            />
+          {showConnectionDetails && details && stream ? (
+            <Row sub>
+              <div id="host-details-panel" style={{ display: "contents" }}>
+                <span
+                  className="lr-meter-tag"
+                  title={vis ? undefined : t("host.captureAria")}
+                >
+                  <Glyph name="arrowUp" size={17} />
+                  {vis ? null : (
+                    <span className="lr-cap">{t("stats.capture")}</span>
+                  )}
+                </span>
+                <div
+                  className="lr-meter"
+                  role="group"
+                  aria-label={t("host.captureAria")}
+                >
+                  <span
+                    className="lr-meter-cell"
+                    title={vis ? undefined : t("stats.resolution")}
+                  >
+                    <Glyph name="expand" size={16} />
+                    <b>
+                      {details.resolution ?? (vis ? "—" : t("stats.unknown"))}
+                    </b>
+                    {vis ? (
+                      <span className="visually-hidden">
+                        {t("stats.resolution")}
+                      </span>
+                    ) : null}
+                  </span>
+                  <span
+                    className="lr-meter-cell"
+                    title={vis ? undefined : t("stats.fps")}
+                  >
+                    <Glyph name="wave" size={16} />
+                    <b>
+                      {details.frameRate
+                        ? `${details.frameRate.toFixed(0)} fps`
+                        : vis
+                          ? "—"
+                          : t("host.capture.fpsUnknown")}
+                    </b>
+                    {vis ? (
+                      <span className="visually-hidden">{t("stats.fps")}</span>
+                    ) : null}
+                  </span>
+                  <span
+                    className="lr-meter-cell"
+                    title={vis ? undefined : t("stats.codec")}
+                  >
+                    <Glyph name="cpu" size={16} />
+                    <b>
+                      {resolvedVideoCodec?.toUpperCase() ??
+                        (vis ? "—" : t("host.capture.codecPending"))}
+                    </b>
+                    {vis ? (
+                      <span className="visually-hidden">{t("stats.codec")}</span>
+                    ) : null}
+                  </span>
+                  <span
+                    className="lr-meter-cell"
+                    title={vis ? undefined : t("stats.audio")}
+                  >
+                    {vis ? (
+                      <span
+                        style={{ position: "relative", display: "inline-flex" }}
+                      >
+                        <Glyph name="speaker" size={16} />
+                        {details.hasAudio ? null : (
+                          <span
+                            aria-hidden="true"
+                            style={{
+                              position: "absolute",
+                              top: -3,
+                              bottom: -3,
+                              left: "50%",
+                              width: 2.5,
+                              borderRadius: 2,
+                              background: "currentColor",
+                              transform: "translateX(-50%) rotate(45deg)",
+                            }}
+                          />
+                        )}
+                        <span className="visually-hidden">
+                          {details.hasAudio
+                            ? t("host.capture.hasAudio")
+                            : t("host.capture.noAudio")}
+                        </span>
+                      </span>
+                    ) : (
+                      <>
+                        <Glyph name="speaker" size={16} />
+                        <b>
+                          {details.hasAudio
+                            ? t("host.capture.hasAudio")
+                            : t("host.capture.noAudio")}
+                        </b>
+                      </>
+                    )}
+                  </span>
+                </div>
+              </div>
+            </Row>
           ) : null}
-          {selectedViewer && selectedDetail ? (
-            <PawnDetail
-              pawnKey={selectedViewer.peerId}
-              name={selectedViewer.label}
-              route={selectedDetail.route}
-              metrics={selectedDetail.metrics}
-              direction={selectedDetail.direction}
-              tag={selectedDetail.tag}
-              error={selectedDetail.error}
-              expanded={metricsExpanded}
-              onToggleMetrics={setMetricsExpanded}
-              onClose={() => setSelectedPawn(null)}
-            />
-          ) : null}
-
           <Row>
             {room ? (
               <RowGroup>
@@ -2937,7 +3013,12 @@ export function HostPage({ onAuthorizationRequired }: HostPageProps = {}) {
                 </form>
               ) : (
                 <>
-                  <NameTag name={hostPresence?.displayName ?? displayName} />
+                  <NameTag
+                    name={hostPresence?.displayName ?? displayName}
+                    identity={
+                      hostPeerId ?? hostClientIdRef.current ?? "host-pending"
+                    }
+                  />
                   {hintWrap(
                     "hint-rename",
                     <Btn
@@ -2973,7 +3054,7 @@ export function HostPage({ onAuthorizationRequired }: HostPageProps = {}) {
                   {hintWrap(
                     "hint-switch-source",
                     <Btn
-                      icon="refresh"
+                      icon="switchSource"
                       cap={switchingSource ? "host.switching" : "host.switchSource"}
                       title="host.switchSource"
                       disabled={switchingSource || changingQuality}
@@ -3578,6 +3659,46 @@ export function HostPage({ onAuthorizationRequired }: HostPageProps = {}) {
             </div>
           </div>
 
+          {showConnectionDetails && viewerOverviewEntries.length > 0 ? (
+            <ViewerOverview
+              entries={viewerOverviewEntries}
+              selectedKey={selectedPawn}
+              onSelect={(peerId) =>
+                setSelectedPawn((current) =>
+                  current === peerId ? null : peerId,
+                )
+              }
+            />
+          ) : null}
+          {selectedViewer && selectedDetail ? (
+            <PawnDetail
+              pawnKey={selectedViewer.peerId}
+              name={selectedViewer.label}
+              route={selectedDetail.route}
+              metrics={selectedDetail.metrics}
+              direction={selectedDetail.direction}
+              tag={selectedDetail.tag}
+              error={selectedDetail.error}
+              expanded={metricsExpanded}
+              onToggleMetrics={setMetricsExpanded}
+              onClose={() => setSelectedPawn(null)}
+            />
+          ) : null}
+          {showTopology ? (
+            <Row sub>
+              <RouteTree
+                hostPeerId={hostPeerId}
+                hostLabel={labeledHostPresence?.label ?? displayName}
+                viewers={viewers}
+                selectedPeerId={selectedPawn}
+                onSelectPeer={(peerId) =>
+                  setSelectedPawn((current) =>
+                    current === peerId ? null : peerId,
+                  )
+                }
+              />
+            </Row>
+          ) : null}
           <Row label={t("host.details")}>
             <RowGroup actions>
               {hintWrap(
@@ -3609,115 +3730,6 @@ export function HostPage({ onAuthorizationRequired }: HostPageProps = {}) {
               )}
             </RowGroup>
           </Row>
-          {showConnectionDetails && details && stream ? (
-            <Row sub>
-              <div id="host-details-panel" style={{ display: "contents" }}>
-              <span
-                className="lr-meter-tag"
-                title={vis ? undefined : t("host.captureAria")}
-              >
-                <Glyph name="arrowUp" size={17} />
-                {vis ? null : (
-                  <span className="lr-cap">{t("stats.capture")}</span>
-                )}
-              </span>
-              <div
-                className="lr-meter"
-                role="group"
-                aria-label={t("host.captureAria")}
-              >
-                <span
-                  className="lr-meter-cell"
-                  title={vis ? undefined : t("stats.resolution")}
-                >
-                  <Glyph name="expand" size={16} />
-                  <b>
-                    {details.resolution ?? (vis ? "—" : t("stats.unknown"))}
-                  </b>
-                </span>
-                <span
-                  className="lr-meter-cell"
-                  title={vis ? undefined : t("stats.fps")}
-                >
-                  <Glyph name="wave" size={16} />
-                  <b>
-                    {details.frameRate
-                      ? `${details.frameRate.toFixed(0)} fps`
-                      : vis
-                        ? "—"
-                        : t("host.capture.fpsUnknown")}
-                  </b>
-                </span>
-                <span
-                  className="lr-meter-cell"
-                  title={vis ? undefined : t("stats.codec")}
-                >
-                  <Glyph name="cpu" size={16} />
-                  <b>
-                    {resolvedVideoCodec?.toUpperCase() ??
-                      (vis ? "—" : t("host.capture.codecPending"))}
-                  </b>
-                </span>
-                <span
-                  className="lr-meter-cell"
-                  title={vis ? undefined : t("stats.audio")}
-                >
-                  {vis ? (
-                    <span
-                      style={{ position: "relative", display: "inline-flex" }}
-                    >
-                      <Glyph name="speaker" size={16} />
-                      {details.hasAudio ? null : (
-                        <span
-                          aria-hidden="true"
-                          style={{
-                            position: "absolute",
-                            top: -3,
-                            bottom: -3,
-                            left: "50%",
-                            width: 2.5,
-                            borderRadius: 2,
-                            background: "currentColor",
-                            transform: "translateX(-50%) rotate(45deg)",
-                          }}
-                        />
-                      )}
-                      <span className="visually-hidden">
-                        {details.hasAudio
-                          ? t("host.capture.hasAudio")
-                          : t("host.capture.noAudio")}
-                      </span>
-                    </span>
-                  ) : (
-                    <>
-                      <Glyph name="speaker" size={16} />
-                      <b>
-                        {details.hasAudio
-                          ? t("host.capture.hasAudio")
-                          : t("host.capture.noAudio")}
-                      </b>
-                    </>
-                  )}
-                </span>
-              </div>
-              </div>
-            </Row>
-          ) : null}
-          {showTopology ? (
-            <Row sub>
-              <RouteTree
-                hostPeerId={hostPeerId}
-                hostLabel={labeledHostPresence?.label ?? displayName}
-                viewers={viewers}
-                selectedPeerId={selectedPawn}
-                onSelectPeer={(peerId) =>
-                  setSelectedPawn((current) =>
-                    current === peerId ? null : peerId,
-                  )
-                }
-              />
-            </Row>
-          ) : null}
         </div>
       </main>
     </div>
diff --git a/src/client/pages/ViewerPage.tsx b/src/client/pages/ViewerPage.tsx
index 6275d4d..8660cd2 100644
--- a/src/client/pages/ViewerPage.tsx
+++ b/src/client/pages/ViewerPage.tsx
@@ -85,10 +85,12 @@ import {
   deriveViewerPresentation,
   reduceViewerPresentation,
   viewerFailureFromServerCode,
+  type ViewerNoticeKey,
   type ViewerPresentationAction,
   type ViewerRouteKind,
   type ViewerStage,
 } from "../media/viewer-presentation";
+import { prepareViewerPlayback } from "../media/viewer-playback";
 import {
   isAutoplayPolicyRejection,
   observeCompositedVideoFrame,
@@ -154,6 +156,9 @@ function stageOverlayGlyph(stage: ViewerStage): { icon: GlyphName; spin: boolean
     case "route-failed":
     case "playback-failed":
     case "server-error":
+    case "stale-client":
+    case "session-replaced":
+    case "signal-terminated":
       return { icon: "alert", spin: false };
     case "recovering":
     case "waiting-sfu":
@@ -191,6 +196,9 @@ function stageOverlayComic(
     case "route-failed":
       return "route-failed";
     case "server-error":
+    case "stale-client":
+    case "session-replaced":
+    case "signal-terminated":
       return "warning";
     case "playback-failed":
       return "playback-failed";
@@ -204,6 +212,19 @@ function stageOverlayComic(
   }
 }
 
+function viewerNoticeVisual(
+  noticeKey: ViewerNoticeKey,
+): { icon: GlyphName; comic: ComicKind } {
+  switch (noticeKey) {
+    case "viewer.notice.hostOffline":
+      return { icon: "wifiOff", comic: "host-offline" };
+    case "viewer.notice.signalRecovering":
+      return { icon: "wifiOff", comic: "recovering" };
+    case "viewer.notice.mediaRecovering":
+      return { icon: "refresh", comic: "recovering" };
+  }
+}
+
 function stageChin(stage: ViewerStage): ChinState {
   switch (stage) {
     case "playing":
@@ -277,6 +298,9 @@ export function ViewerPage({ roomId, viewerGrant }: ViewerPageProps) {
   const [participantPresence, setParticipantPresence] = useState<
     ParticipantPresenceEntry[] | null
   >(null);
+  const [lastHostDisplayName, setLastHostDisplayName] = useState<string | null>(
+    null,
+  );
   const [viewerPasswordDraft, setViewerPasswordDraft] = useState("");
   const [viewerPasswordError, setViewerPasswordError] = useState<CopyKey | null>(
     null,
@@ -286,7 +310,6 @@ export function ViewerPage({ roomId, viewerGrant }: ViewerPageProps) {
     sequence: number;
   } | null>(null);
   const [viewerPasswordExpanded, setViewerPasswordExpanded] = useState(false);
-  const [frameProofEpoch, setFrameProofEpoch] = useState(0);
   // Presentation-only: which couch pawn is drilled into, and this viewer's
   // own peer id (mirrors the authenticated message for couch/route-tree).
   const [selectedPawn, setSelectedPawn] = useState<string | null>(null);
@@ -297,6 +320,8 @@ export function ViewerPage({ roomId, viewerGrant }: ViewerPageProps) {
     useMetricsExpanded();
   const [pawnMetricsExpanded, setPawnMetricsExpanded] = useMetricsExpanded();
 
+  const mediaProofGeneration = presentationState.media?.generation ?? null;
+  const mediaProofEpoch = presentationState.media?.proofEpoch ?? null;
   useEffect(() => {
     if (!theaterMode) return;
     const exitOnEscape = (event: KeyboardEvent) => {
@@ -323,7 +348,8 @@ export function ViewerPage({ roomId, viewerGrant }: ViewerPageProps) {
     () => labelParticipantSnapshot(participantPresence ?? []),
     [participantPresence],
   );
-  const hostDisplayName = labeledHostPresence?.label ?? null;
+  const currentHostDisplayName = labeledHostPresence?.label ?? null;
+  const hostDisplayName = currentHostDisplayName ?? lastHostDisplayName;
   const titleFrameKey =
     presentationState.host === "paused"
       ? "paused"
@@ -341,12 +367,16 @@ export function ViewerPage({ roomId, viewerGrant }: ViewerPageProps) {
 
   function clearParticipantPresence(): void {
     setParticipantPresence(null);
+    setLastHostDisplayName(null);
   }
 
-  function clearHostPresence(): void {
+  function clearHostPresence(forgetDisplayName = true): void {
     setParticipantPresence((current) =>
       current?.filter((participant) => participant.role !== "host") ?? null,
     );
+    if (forgetDisplayName) {
+      setLastHostDisplayName(null);
+    }
   }
 
   const videoRef = useRef<HTMLVideoElement | null>(null);
@@ -444,6 +474,17 @@ export function ViewerPage({ roomId, viewerGrant }: ViewerPageProps) {
     });
   }
 
+  function rearmCurrentFrameProof(): void {
+    const binding = remoteMediaRef.current;
+    if (!binding) {
+      return;
+    }
+    dispatchPresentation({
+      type: "frame-proof-rearm",
+      generation: binding.generation,
+    });
+  }
+
   function invalidateQualityPresentation(): void {
     qualityEvidenceReporterRef.current?.invalidatePresentation();
     qualityFrameProofGenerationRef.current = null;
@@ -580,7 +621,6 @@ export function ViewerPage({ roomId, viewerGrant }: ViewerPageProps) {
       syncDecodedFrameStallPause();
       if (pageSuspended) return;
       decodedFrameStall.rebaseline();
-      setFrameProofEpoch((current) => current + 1);
     };
     const handleVisibilityChange = (): void => {
       if (document.visibilityState === "visible") {
@@ -685,7 +725,6 @@ export function ViewerPage({ roomId, viewerGrant }: ViewerPageProps) {
           binding &&
           qualityFrameProofGenerationRef.current === binding.generation &&
           state.routeStatus?.state !== "failed" &&
-          state.failure !== "ROUTE_EXHAUSTED" &&
           video &&
           !video.paused &&
           !video.ended,
@@ -701,7 +740,9 @@ export function ViewerPage({ roomId, viewerGrant }: ViewerPageProps) {
         qualityPresentationEligible(connectionHealthy);
       if (!connectionHealthy) {
         invalidatePresentedMedia();
-      } else if (!qualityEligible) {
+        return;
+      }
+      if (!qualityEligible) {
         invalidateQualityPresentation();
       }
       qualityEvidenceReporter.offer(
@@ -1114,7 +1155,8 @@ export function ViewerPage({ roomId, viewerGrant }: ViewerPageProps) {
               if (
                 currentRouteAssignment?.upstream.kind === "sfu" &&
                 currentRouteConnectionId &&
-                revision === currentRouteRevision
+                revision === currentRouteRevision &&
+                sfuTransportConnected
               ) {
                 qualityEvidenceReporter.offerMetrics(
                   currentRouteConnectionId,
@@ -1460,10 +1502,7 @@ export function ViewerPage({ roomId, viewerGrant }: ViewerPageProps) {
                   snapshot.connectionState === "closed")
               ) {
                 clearPeerState();
-                dispatchPresentation({
-                  type: "media-invalidated",
-                  revision: currentRouteRevision,
-                });
+                invalidatePresentedMedia();
                 return;
               }
               setPeerSnapshot(snapshot);
@@ -1489,9 +1528,9 @@ export function ViewerPage({ roomId, viewerGrant }: ViewerPageProps) {
             }
             invalidateQualityPresentation();
             dispatchPresentation({
-              type: "failure",
-              failure: "ROUTE_EXHAUSTED",
+              type: "route-status",
               revision: currentRouteRevision,
+              state: "failed",
             });
             return true;
           },
@@ -1828,6 +1867,10 @@ export function ViewerPage({ roomId, viewerGrant }: ViewerPageProps) {
         return;
       }
       if (message.type === "viewer-presence") {
+        const hostLabel = labelParticipantSnapshot(message.viewers).host?.label;
+        if (hostLabel) {
+          setLastHostDisplayName(hostLabel);
+        }
         setParticipantPresence(message.viewers);
         return;
       }
@@ -1890,7 +1933,7 @@ export function ViewerPage({ roomId, viewerGrant }: ViewerPageProps) {
       if (message.type === "error") {
         if (message.code === "PEER_NOT_FOUND" && !currentHostOnline) {
           clearPeerState();
-          clearHostPresence();
+          clearHostPresence(false);
           dispatchPresentation({ type: "host", host: "offline" });
           return;
         }
@@ -1931,10 +1974,8 @@ export function ViewerPage({ roomId, viewerGrant }: ViewerPageProps) {
           return;
         }
         const failure = viewerFailureFromServerCode(message.code);
-        if (failure) {
-          dispatchPresentation({ type: "failure", failure });
-        } else if (message.code !== "PEER_NOT_FOUND") {
-          dispatchPresentation({ type: "failure", failure: "SERVER_ERROR" });
+        if (failure === "SERVER_ERROR") {
+          dispatchPresentation({ type: "server-error" });
         }
       }
     }
@@ -1981,15 +2022,13 @@ export function ViewerPage({ roomId, viewerGrant }: ViewerPageProps) {
       }
       return;
     }
-    const streamChanged = video.srcObject !== remoteMedia.stream;
-    if (streamChanged) {
-      video.srcObject = remoteMedia.stream;
-    }
-    if (presentationState.host === "paused") {
-      video.pause();
-      return;
-    }
-    if (streamChanged) {
+    if (
+      prepareViewerPlayback(
+        video,
+        remoteMedia.stream,
+        presentationState.host === "paused",
+      )
+    ) {
       attemptPlayback(video, remoteMedia);
     }
   }, [remoteMedia]);
@@ -2019,22 +2058,42 @@ export function ViewerPage({ roomId, viewerGrant }: ViewerPageProps) {
 
   useEffect(() => {
     const video = videoRef.current;
-    if (!video || !remoteMedia) {
+    const mediaFact = presentationState.media;
+    if (
+      !video ||
+      !remoteMedia ||
+      !mediaFact ||
+      mediaFact.generation !== remoteMedia.generation ||
+      presentationState.host === "paused" ||
+      document.visibilityState !== "visible"
+    ) {
       return;
     }
     const binding = remoteMedia;
+    const proofEpoch = mediaFact.proofEpoch;
     return observeCompositedVideoFrame(video, binding.stream, () => {
-      if (!mediaBindingIsCurrent(binding)) {
+      const currentMedia = presentationStateRef.current.media;
+      if (
+        !mediaBindingIsCurrent(binding) ||
+        currentMedia?.generation !== binding.generation ||
+        currentMedia.proofEpoch !== proofEpoch
+      ) {
         return;
       }
       qualityFrameProofGenerationRef.current = binding.generation;
       dispatchPresentation({
         type: "frame-presented",
         generation: binding.generation,
+        proofEpoch,
         revision: binding.boundAtRevision,
       });
     });
-  }, [frameProofEpoch, presentationState.connection, remoteMedia]);
+  }, [
+    mediaProofEpoch,
+    mediaProofGeneration,
+    presentationState.host,
+    remoteMedia,
+  ]);
 
   function retryConnection(): void {
     if (reconnectRoute === "sfu") {
@@ -2085,43 +2144,44 @@ export function ViewerPage({ roomId, viewerGrant }: ViewerPageProps) {
   }
 
   if (accessState !== "ready") {
+    const failureCode = presentation.failureCode;
     const codeOnlyDenied =
-      !viewerGrant && presentationState.failure === "ROOM_ACCESS_DENIED";
+      !viewerGrant && failureCode === "ROOM_ACCESS_DENIED";
     const canRefresh = [
       "STALE_CLIENT",
       "SERVER_ERROR",
       "SESSION_REPLACED",
       "SIGNAL_TERMINATED",
-    ].includes(presentationState.failure ?? "");
+    ].includes(failureCode ?? "");
     const deniedComic: ComicKind =
-      presentationState.failure === "ROOM_FULL"
+      failureCode === "ROOM_FULL"
         ? "room-full"
         : codeOnlyDenied
           ? "access-denied"
-          : presentationState.failure === "INVALID_TOKEN"
+          : failureCode === "INVALID_TOKEN"
             ? "invalid-invite"
-            : presentationState.failure === "ROOM_NOT_FOUND" ||
-                presentationState.failure === "ROOM_EXPIRED" ||
-                presentationState.failure === "ROOM_CLOSED"
+            : failureCode === "ROOM_NOT_FOUND" ||
+                failureCode === "ROOM_EXPIRED" ||
+                failureCode === "ROOM_CLOSED"
               ? "room-not-found"
               : "warning";
     const deniedIcon: GlyphName =
-      presentationState.failure === "ROOM_NOT_FOUND" ||
-      presentationState.failure === "ROOM_EXPIRED" ||
-      presentationState.failure === "ROOM_CLOSED"
+      failureCode === "ROOM_NOT_FOUND" ||
+      failureCode === "ROOM_EXPIRED" ||
+      failureCode === "ROOM_CLOSED"
         ? "door"
-        : presentationState.failure === "ROOM_ACCESS_DENIED"
+        : failureCode === "ROOM_ACCESS_DENIED"
           ? "lock"
-          : presentationState.failure === "ROOM_FULL"
+          : failureCode === "ROOM_FULL"
             ? "users"
             : "alert";
     const deniedHintKey: CopyKey = codeOnlyDenied
       ? "viewer.hint.denied"
-      : presentationState.failure === "ROOM_NOT_FOUND" ||
-          presentationState.failure === "ROOM_EXPIRED" ||
-          presentationState.failure === "ROOM_CLOSED"
+      : failureCode === "ROOM_NOT_FOUND" ||
+          failureCode === "ROOM_EXPIRED" ||
+          failureCode === "ROOM_CLOSED"
         ? "viewer.hint.notFound"
-        : presentationState.failure === "INVALID_TOKEN"
+        : failureCode === "INVALID_TOKEN"
           ? "viewer.hint.invite"
           : "viewer.hint.generic";
     return (
@@ -2153,7 +2213,7 @@ export function ViewerPage({ roomId, viewerGrant }: ViewerPageProps) {
                 <>
                   <Comic kind={deniedComic} theme="paper" />
                   <span className="visually-hidden" role="alert">
-                    {t(presentation.messageKey)}
+                    {t(presentation.messageKey)} · {t(deniedHintKey)}
                   </span>
                 </>
               ) : (
@@ -2171,9 +2231,7 @@ export function ViewerPage({ roomId, viewerGrant }: ViewerPageProps) {
                 <Glyph name={deniedIcon} size={30} />
               </span>
               )}
-              {vis ? (
-                <Pill icon="alert" tone="bad" label={t(deniedHintKey)} />
-              ) : (
+              {vis ? null : (
                 <div className="lr-access-text">
                   <h1>{t(presentation.messageKey)}</h1>
                   <p>{t(deniedHintKey)}</p>
@@ -2254,6 +2312,9 @@ export function ViewerPage({ roomId, viewerGrant }: ViewerPageProps) {
     presentation.stage,
     assignedRouteKind,
   );
+  const noticeVisual = presentation.noticeKey
+    ? viewerNoticeVisual(presentation.noticeKey)
+    : null;
   const selectedChildEvidence =
     selectedPawn !== null &&
     selectedPawn !== selfPeerId &&
@@ -2341,10 +2402,11 @@ export function ViewerPage({ roomId, viewerGrant }: ViewerPageProps) {
                 (presentation.stage === "receiving" &&
                   presentation.hasRetainedFrame)
               }
+              controlsList={theaterMode ? "nofullscreen" : undefined}
               playsInline
               onPlay={() => {
                 invalidateQualityPresentation();
-                setFrameProofEpoch((current) => current + 1);
+                rearmCurrentFrameProof();
                 const binding = remoteMediaRef.current;
                 if (binding) {
                   dispatchPresentation({
@@ -2390,6 +2452,45 @@ export function ViewerPage({ roomId, viewerGrant }: ViewerPageProps) {
                 />
               )}
           </StageTv>
+          {(presentation.noticeKey ||
+            (routePresentation.evidence === peerSnapshot &&
+              peerSnapshot?.error) ||
+            relaySnapshot?.error ||
+            qualityLimitation) && (
+            <div className="lr-stage-notices">
+              {presentation.noticeKey && noticeVisual ? (
+                <Pill
+                  icon={noticeVisual.icon}
+                  label={t(presentation.noticeKey)}
+                  comic={noticeVisual.comic}
+                />
+              ) : null}
+              {routePresentation.evidence === peerSnapshot &&
+              peerSnapshot?.error ? (
+                <Pill
+                  icon="alert"
+                  tone="bad"
+                  label={t("viewer.error.p2p")}
+                  comic="warning"
+                />
+              ) : null}
+              {relaySnapshot?.error ? (
+                <Pill
+                  icon="alert"
+                  tone="bad"
+                  label={t("viewer.error.relay")}
+                  comic="warning"
+                />
+              ) : null}
+              {qualityLimitation ? (
+                <Pill
+                  icon="alert"
+                  label={qualityLimitation}
+                  comic="warning"
+                />
+              ) : null}
+            </div>
+          )}
           {theaterMode ? (
             <div className="lr-theater-exit">
               <Btn
@@ -2444,138 +2545,154 @@ export function ViewerPage({ roomId, viewerGrant }: ViewerPageProps) {
             <div className="lr-row-group lr-viewer-state-slot">
               <StatusText>{t(presentation.messageKey)}</StatusText>
             </div>
-            <form
-              className="lr-row-group lr-group-name lr-viewer-self-slot"
-              onSubmit={(event) => {
-                event.preventDefault();
-                commitDisplayName();
-              }}
-            >
-              {editingDisplayName ? (
-                <>
-                  <span className="lr-input lr-name-editor">
-                    <input
-                      id="viewer-display-name"
-                      type="text"
-                      value={displayNameDraft}
-                      maxLength={96}
-                      autoComplete="nickname"
-                      autoFocus
-                      aria-label={t("host.name")}
-                      aria-invalid={displayNameError ? "true" : undefined}
-                      onChange={(event) => {
-                        setDisplayNameDraft(event.target.value);
-                        setDisplayNameError(false);
-                      }}
-                    />
-                  </span>
-                  <Btn
-                    icon="check"
-                    title="host.nameSave"
-                    type="submit"
-                    disabled={displayNameDraft === displayName}
-                  />
-                  <Btn
-                    icon="x"
-                    title="host.nameCancel"
-                    onClick={() => {
-                      setDisplayNameDraft(displayName);
-                      setDisplayNameError(false);
-                      setEditingDisplayName(false);
-                    }}
-                  />
-                </>
-              ) : (
-                <>
-                  <NameTag name={displayName} />
-                  {hintWrap(
-                    "hint-rename",
+            <div className="lr-viewer-personal-controls">
+              <form
+                className="lr-row-group lr-group-name lr-viewer-self-slot"
+                onSubmit={(event) => {
+                  event.preventDefault();
+                  commitDisplayName();
+                }}
+              >
+                {editingDisplayName ? (
+                  <>
+                    <span className="lr-input lr-name-editor">
+                      <input
+                        id="viewer-display-name"
+                        type="text"
+                        value={displayNameDraft}
+                        maxLength={96}
+                        autoComplete="nickname"
+                        autoFocus
+                        aria-label={t("host.name")}
+                        aria-invalid={displayNameError ? "true" : undefined}
+                        onChange={(event) => {
+                          setDisplayNameDraft(event.target.value);
+                          setDisplayNameError(false);
+                        }}
+                      />
+                    </span>
                     <Btn
-                      icon="pencil"
-                      cap="common.edit"
-                      title="host.nameEdit"
+                      icon="check"
+                      title="host.nameSave"
+                      type="submit"
+                      disabled={displayNameDraft === displayName}
+                    />
+                    <Btn
+                      icon="x"
+                      title="host.nameCancel"
                       onClick={() => {
                         setDisplayNameDraft(displayName);
                         setDisplayNameError(false);
-                        setEditingDisplayName(true);
+                        setEditingDisplayName(false);
                       }}
+                    />
+                  </>
+                ) : (
+                  <>
+                    <NameTag
+                      name={displayName}
+                      identity={selfPeerId ?? viewerClientId}
+                    />
+                    {hintWrap(
+                      "hint-rename",
+                      <Btn
+                        icon="pencil"
+                        cap="common.edit"
+                        title="host.nameEdit"
+                        onClick={() => {
+                          setDisplayNameDraft(displayName);
+                          setDisplayNameError(false);
+                          setEditingDisplayName(true);
+                        }}
+                      />,
+                      "end",
+                    )}
+                  </>
+                )}
+                {displayNameError && (
+                  <Pill
+                    icon="alert"
+                    tone="bad"
+                    label={t("host.nameError")}
+                    alert
+                    comic="warning"
+                  />
+                )}
+              </form>
+              <div className="lr-row-group lr-group-actions lr-viewer-actions-slot">
+                <span className="lr-viewer-action-cluster">
+                  <Btn
+                    icon={theaterMode ? "contract" : "expand"}
+                    cap={theaterMode ? "viewer.theater.exit" : "viewer.theater"}
+                    title={
+                      theaterMode ? "viewer.theater.exit" : "viewer.theater"
+                    }
+                    tone={theaterMode ? "on" : undefined}
+                    pressed={theaterMode}
+                    controls="viewer-stage"
+                    onClick={() => setTheaterMode((current) => !current)}
+                  />
+                  {hintWrap(
+                    "hint-reconnect",
+                    <Btn
+                      icon="refresh"
+                      cap="viewer.reconnect"
+                      title="viewer.reconnect"
+                      disabled={!reconnectAvailable}
+                      onClick={retryConnection}
                     />,
                     "end",
                   )}
-                </>
-              )}
-              {displayNameError && (
-                <Pill icon="alert" tone="bad" label={t("host.nameError")} alert />
-              )}
-            </form>
-            <div className="lr-row-group lr-group-actions lr-viewer-actions-slot">
-              <Btn
-                icon={theaterMode ? "contract" : "expand"}
-                cap={theaterMode ? "viewer.theater.exit" : "viewer.theater"}
-                title={theaterMode ? "viewer.theater.exit" : "viewer.theater"}
-                tone={theaterMode ? "on" : undefined}
-                pressed={theaterMode}
-                controls="viewer-stage"
-                onClick={() => setTheaterMode((current) => !current)}
-              />
-              {labeledHostPresence
-                ? hintWrap(
-                    "hint-topology",
-                    <Btn
-                      icon="network"
-                      cap="host.topology"
-                      title={
-                        showTopology ? "host.topology.hide" : "host.topology.show"
-                      }
-                      tone={showTopology ? "on" : undefined}
-                      expanded={showTopology}
-                      controls="room-topology"
-                      onClick={() => setShowTopology((current) => !current)}
-                    />,
-                    "start",
-                  )
-                : null}
-              {hintWrap(
-                "hint-reconnect",
-                <Btn
-                  icon="refresh"
-                  cap="viewer.reconnect"
-                  title="viewer.reconnect"
-                  disabled={!reconnectAvailable}
-                  onClick={retryConnection}
-                />,
-                "end",
-              )}
-              <Btn
-                icon="gauge"
-                cap="host.details"
-                title={showConnectionDetails ? "host.details.hide" : "host.details"}
-                hint="hint-details"
-                tone={showConnectionDetails ? "on" : undefined}
-                expanded={showConnectionDetails}
-                controls="viewer-details-panel"
-                disabled={
-                  !routePresentation.route &&
-                  !relaySnapshot &&
-                  !relayChildEvidence
-                }
-                onClick={() => setShowConnectionDetails((current) => !current)}
-              />
+                </span>
+                <span
+                  className="lr-viewer-action-separator"
+                  aria-hidden="true"
+                />
+                <span className="lr-viewer-action-cluster">
+                  <Btn
+                    icon="gauge"
+                    cap="host.details"
+                    title={
+                      showConnectionDetails ? "host.details.hide" : "host.details"
+                    }
+                    hint="hint-details"
+                    tone={showConnectionDetails ? "on" : undefined}
+                    expanded={showConnectionDetails}
+                    controls="viewer-details-panel"
+                    disabled={
+                      !routePresentation.route &&
+                      !relaySnapshot &&
+                      !relayChildEvidence
+                    }
+                    onClick={() =>
+                      setShowConnectionDetails((current) => !current)
+                    }
+                  />
+                  {labeledHostPresence
+                    ? hintWrap(
+                        "hint-topology",
+                        <Btn
+                          icon="network"
+                          cap="host.topology"
+                          title={
+                            showTopology
+                              ? "host.topology.hide"
+                              : "host.topology.show"
+                          }
+                          tone={showTopology ? "on" : undefined}
+                          expanded={showTopology}
+                          controls="room-topology"
+                          onClick={() =>
+                            setShowTopology((current) => !current)
+                          }
+                        />,
+                        "start",
+                      )
+                    : null}
+                </span>
+              </div>
             </div>
           </div>
-          {presentation.noticeKey ? (
-            <Pill icon="alert" label={t(presentation.noticeKey)} />
-          ) : null}
-          {routePresentation.evidence === peerSnapshot &&
-          peerSnapshot?.error ? (
-            <Pill icon="alert" tone="bad" label={t("viewer.error.p2p")} comic="warning" />
-          ) : null}
-          {relaySnapshot?.error ? (
-            <Pill icon="alert" tone="bad" label={t("viewer.error.relay")} comic="warning" />
-          ) : null}
-          {qualityLimitation ? (
-            <Pill icon="alert" label={qualityLimitation} comic="warning" />
-          ) : null}
           {showConnectionDetails && routePresentation.route ? (
             <Row sub>
               <div id="viewer-details-panel" style={{ display: "contents" }}>
diff --git a/src/client/sfu/publisher.ts b/src/client/sfu/publisher.ts
index 9b1671d..e4ace66 100644
--- a/src/client/sfu/publisher.ts
+++ b/src/client/sfu/publisher.ts
@@ -121,6 +121,7 @@ export class SfuPublisher {
   private statsInFlight: PublisherStatsIdentity | null = null;
   private statsTimer: ReturnType<typeof setInterval> | null = null;
   private startupVideoProfilePending = false;
+  private paused = false;
 
   constructor(private readonly events: PublisherEvents = {}) {}
 
@@ -772,6 +773,7 @@ export class SfuPublisher {
   }
 
   setPaused(paused: boolean): void {
+    this.paused = paused;
     if (this.video) {
       this.video.rawTrack.enabled = !paused;
     }
@@ -843,10 +845,12 @@ export class SfuPublisher {
         let retainedNextTrack = false;
         try {
           await applyVideoCaptureProfile(nextRawTrack, profile);
+          nextRawTrack.enabled = !this.paused;
           await replacePublishedTrack(video, nextRawTrack);
           if (!this.owns(room, generation)) {
             return false;
           }
+          nextRawTrack.enabled = !this.paused;
           video.rawTrack = nextRawTrack;
           retainedNextTrack = true;
           previousRawTrack.stop();
@@ -1162,6 +1166,7 @@ export class SfuPublisher {
           : {
               qualityLimitationReason:
                 nativeQuality.qualityLimitationReason,
+              sampleTimestampMs: nativeQuality.sampleTimestampMs,
               sampleWindowMs: nativeQuality.sampleWindowMs,
               intervalFramesEncoded: nativeQuality.intervalFramesEncoded,
             }),
diff --git a/src/client/styles.css b/src/client/styles.css
index 0f30037..b54d62c 100644
--- a/src/client/styles.css
+++ b/src/client/styles.css
@@ -211,27 +211,27 @@ ul { margin: 0; padding: 0; list-style: none; }
   to { opacity: 1; transform: scale(1); }
 }
 @keyframes lr-brand-eye-open {
-  0%, 24%, 34%, 100% { opacity: 0; transform: scaleY(.15); }
-  27%, 30% { opacity: 1; transform: scale(1); }
+  0%, 34% { opacity: 1; transform: scale(1); }
+  38%, 100% { opacity: 0; transform: scaleY(.15); }
 }
 @keyframes lr-brand-eye-wink {
-  0%, 24%, 35%, 100% { opacity: 1; stroke-dasharray: 1; stroke-dashoffset: 0; }
-  27%, 30% { opacity: 0; stroke-dasharray: 1; stroke-dashoffset: 1; }
-  32% { opacity: 1; stroke-dasharray: 1; stroke-dashoffset: 1; }
+  0%, 34% { opacity: 0; stroke-dasharray: 1; stroke-dashoffset: 1; }
+  38% { opacity: 1; stroke-dasharray: 1; stroke-dashoffset: 1; }
+  44%, 100% { opacity: 1; stroke-dasharray: 1; stroke-dashoffset: 0; }
 }
 @keyframes lr-brand-sparkle {
-  0%, 30% { opacity: 0; transform: translate(-1px, 2px) scale(.12) rotate(-20deg); }
-  36% { opacity: 1; transform: translate(0, 0) scale(.85) rotate(0); }
-  52% { opacity: .9; transform: translate(5px, -5px) scale(1) rotate(18deg); }
-  70% { opacity: .35; transform: translate(9px, -9px) scale(.55) rotate(34deg); }
-  78%, 100% { opacity: 0; transform: translate(12px, -12px) scale(.2) rotate(48deg); }
+  0%, 42% { opacity: 0; transform: translate(-1px, 2px) scale(.12) rotate(-20deg); }
+  48% { opacity: 1; transform: translate(0, 0) scale(.85) rotate(0); }
+  60% { opacity: .9; transform: translate(5px, -5px) scale(1) rotate(18deg); }
+  74% { opacity: .35; transform: translate(9px, -9px) scale(.55) rotate(34deg); }
+  82%, 100% { opacity: 0; transform: translate(12px, -12px) scale(.2) rotate(48deg); }
 }
 @keyframes lr-brand-sparkle-alt {
-  0%, 30% { opacity: 0; transform: translate(-1px, -1px) scale(.12) rotate(18deg); }
-  36% { opacity: .95; transform: translate(0, 0) scale(.75) rotate(0); }
-  52% { opacity: .8; transform: translate(4px, 4px) scale(.95) rotate(-16deg); }
-  70% { opacity: .3; transform: translate(8px, 8px) scale(.5) rotate(-30deg); }
-  78%, 100% { opacity: 0; transform: translate(11px, 11px) scale(.18) rotate(-42deg); }
+  0%, 42% { opacity: 0; transform: translate(-1px, -1px) scale(.12) rotate(18deg); }
+  48% { opacity: .95; transform: translate(0, 0) scale(.75) rotate(0); }
+  60% { opacity: .8; transform: translate(4px, 4px) scale(.95) rotate(-16deg); }
+  74% { opacity: .3; transform: translate(8px, 8px) scale(.5) rotate(-30deg); }
+  82%, 100% { opacity: 0; transform: translate(11px, 11px) scale(.18) rotate(-42deg); }
 }
 .lr-brand-sparkles { stroke: #d08a22; }
 html[data-theme="dark"] .lr-brand-sparkles { stroke: #f4c14d; }
@@ -582,6 +582,7 @@ body.lr-theater-open { overflow: hidden; }
 .lr-pawns.is-crowded .lr-pawn svg { width: 29px; height: 35px; }
 .lr-pawns.is-crowded .lr-pawn-led { width: 8px; height: 8px; }
 .lr-pawn-name {
+  max-width: 112px;
   margin-top: -4px;
   padding: 1px 6px;
   border-radius: 7px;
@@ -589,9 +590,12 @@ body.lr-theater-open { overflow: hidden; }
   color: var(--ink);
   font-size: 10px;
   font-weight: 700;
+  overflow: hidden;
+  text-overflow: ellipsis;
   white-space: nowrap;
   box-shadow: 0 1px 0 rgba(0, 0, 0, .12);
 }
+.lr-pawns.is-crowded .lr-pawn-name { max-width: 80px; }
 .lr-couch-count {
   position: absolute;
   right: 4%;
@@ -651,7 +655,8 @@ body.lr-theater-open { overflow: hidden; }
 }
 .lr-viewer-room-slot { flex: 0 0 auto; }
 .lr-viewer-host-slot {
-  flex: 0 1 auto;
+  flex: 0 1 180px;
+  min-width: min(96px, 30vw);
   max-width: 180px;
   flex-wrap: nowrap;
   font-size: 13px;
@@ -672,12 +677,33 @@ html[data-theme="dark"] .lr-viewer-host-slot svg { color: #9bb0c5; }
   flex: 0 1 auto;
   align-items: center;
   gap: 8px;
+  margin-left: 0;
+}
+.lr-viewer-personal-controls {
+  display: flex;
+  min-width: 0;
   margin-left: auto;
+  flex: 0 1 auto;
+  flex-wrap: wrap;
+  align-items: center;
+  gap: 8px;
 }
 .lr-viewer-actions-slot {
   flex: 0 0 auto;
   margin-left: 0;
 }
+.lr-viewer-action-cluster {
+  display: inline-flex;
+  min-width: 0;
+  align-items: center;
+  gap: 8px;
+}
+.lr-viewer-action-separator {
+  width: 2.5px;
+  align-self: stretch;
+  border-radius: 2px;
+  background: var(--wall-2);
+}
 .lr-viewer-self-slot .lr-name-tag { flex: 0 1 auto; width: auto; }
 .lr-spacer { flex: 1; }
 .lr-divider { width: 2.5px; align-self: stretch; border-radius: 2px; background: var(--wall-2); }
@@ -923,7 +949,9 @@ html[data-theme="dark"] .lr-invite-url { background: #1a2634; border-color: #334
   display: inline-flex;
   align-items: center;
   gap: 7px;
-  padding: 8px 13px;
+  height: 40px;
+  padding: 0 13px;
+  box-sizing: border-box;
   border: 2.5px solid var(--ink);
   border-radius: 999px;
   background: var(--paper);
@@ -931,6 +959,14 @@ html[data-theme="dark"] .lr-invite-url { background: #1a2634; border-color: #334
   font-weight: 700;
   max-width: 100%;
 }
+.lr-stage-notices {
+  display: flex;
+  width: min(960px, 100%);
+  margin: 10px auto 0;
+  flex-wrap: wrap;
+  justify-content: center;
+  gap: 8px;
+}
 .lr-name-tag i { width: 9px; height: 9px; border-radius: 50%; background: var(--you); flex: 0 0 auto; }
 .lr-name-tag span { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
 
@@ -1331,10 +1367,26 @@ html[data-theme="dark"] .lr-switch::after { background: var(--ink); }
   .lr-row-group { width: 100%; gap: 9px; }
   .lr-viewer-summary-row { flex-direction: row; align-items: center; }
   .lr-viewer-summary-row .lr-row-group { width: auto; }
-  .lr-viewer-host-slot { flex: 0 1 auto; max-width: 180px; }
+  .lr-viewer-host-slot {
+    flex: 0 1 180px;
+    min-width: min(96px, 30vw);
+    max-width: 180px;
+  }
   .lr-viewer-state-slot { flex: 1 1 120px; }
   .lr-viewer-self-slot { flex: 1 1 auto; gap: 6px; margin-left: 0; }
+  .lr-viewer-personal-controls {
+    width: 100%;
+    margin-left: 0;
+  }
   .lr-viewer-actions-slot { flex: 1 1 100%; margin-left: 0; }
+  .lr-viewer-action-cluster { flex: 1 1 220px; }
+  .lr-viewer-action-cluster > .lr-btn,
+  .lr-viewer-action-cluster > .lr-comic-tip-wrap {
+    flex: 1 1 0;
+    min-width: 0;
+  }
+  .lr-viewer-action-cluster > .lr-comic-tip-wrap .lr-btn { width: 100%; }
+  .lr-viewer-action-separator { display: none; }
   .lr-input.lr-name-editor { width: min(136px, 40vw); }
   .lr-group-actions { display: flex; width: 100%; gap: 8px; min-width: 0; }
   .lr-group-actions .lr-btn { flex: 1 1 0; min-width: 0; min-height: 52px; padding: 4px 5px; gap: 6px; }
@@ -1356,6 +1408,16 @@ html[data-theme="dark"] .lr-switch::after { background: var(--ink); }
   .lr-leds-label { display: none; }
   .lr-header-controls .lr-btn .lr-cap { display: none; }
 }
+
+.lr-room.is-theater .lr-stage-notices {
+  position: absolute;
+  z-index: 3;
+  left: 50%;
+  bottom: max(18px, env(safe-area-inset-bottom));
+  width: min(92vw, 720px);
+  margin: 0;
+  transform: translateX(-50%);
+}
 @media (max-width: 360px) {
   .lr-top { gap: 6px; padding-inline: 10px; }
   .lr-top-right { gap: 6px; }
@@ -1389,16 +1451,15 @@ html[data-theme="dark"] .lr-switch::after { background: var(--ink); }
 
 /* ---------- comic tooltip ---------- */
 
-/* Pure-CSS hover/focus panel carrying a paper Comic above its trigger. The
-   trigger inside the wrapper stays the focusable element (touch = focus), so
-   no tabindex here. Enter is delayed ~120ms, exit is immediate. Under
+/* Stateful hover/focus panel carrying a paper Comic above its trigger. The
+   trigger stays focusable; when it is natively disabled, the wrapper owns the
+   explanation focus instead. Enter is delayed ~120ms, exit is immediate. Under
    prefers-reduced-motion the global block collapses the transition to instant
    and the comic's own RM block pins its final frame. */
-/* Visibility is three-channel: hover on fine pointers only (touch would
-   leave sticky-hover stuck), keyboard focus via :has(:focus-visible) (touch
-   taps never match, so no stuck tooltip after activation), and .is-tip-open
-   from the component's Material-style long-press handling. */
+/* Visibility is three-channel state owned by ComicTooltip: fine-pointer hover,
+   keyboard focus-visible, and Material-style touch long-press. */
 .lr-comic-tip-wrap { position: relative; display: inline-flex; }
+.lr-comic-tip-wrap.is-disabled-trigger > :disabled { pointer-events: none; }
 .lr-comic-tip {
   position: absolute;
   bottom: calc(100% + 8px);
@@ -1444,12 +1505,12 @@ html[data-theme="dark"] .lr-switch::after { background: var(--ink); }
 
 /* channel 1: fine-pointer hover */
 @media (hover: hover) and (pointer: fine) {
-  .lr-comic-tip-wrap:hover .lr-comic-tip { opacity: 1; transform: translateX(-50%) translateY(0); transition-delay: .12s; }
-  .lr-comic-tip-wrap:hover .lr-comic-tip * { animation-play-state: running !important; }
-  .lr-comic-tip-wrap:hover .lr-comic-tip.is-below { transform: translateX(-50%) translateY(0); }
-  .lr-comic-tip-wrap:hover .lr-comic-tip.is-start,
-  .lr-comic-tip-wrap:hover .lr-comic-tip.is-end { transform: translateX(0) translateY(0); }
-  .lr-comic-tip-wrap:hover::before { opacity: 1; transform: rotate(45deg) scale(1); transition-delay: .12s; }
+  .lr-comic-tip-wrap.is-hover-open .lr-comic-tip { opacity: 1; transform: translateX(-50%) translateY(0); transition-delay: .12s; }
+  .lr-comic-tip-wrap.is-hover-open .lr-comic-tip * { animation-play-state: running !important; }
+  .lr-comic-tip-wrap.is-hover-open .lr-comic-tip.is-below { transform: translateX(-50%) translateY(0); }
+  .lr-comic-tip-wrap.is-hover-open .lr-comic-tip.is-start,
+  .lr-comic-tip-wrap.is-hover-open .lr-comic-tip.is-end { transform: translateX(0) translateY(0); }
+  .lr-comic-tip-wrap.is-hover-open::before { opacity: 1; transform: rotate(45deg) scale(1); transition-delay: .12s; }
 
   /* Panel mutex: keyboard focus (channel 2) can hold one wrap's panel open
      while the pointer hovers a neighboring trigger, and two 320px panels at
@@ -1458,38 +1519,38 @@ html[data-theme="dark"] .lr-switch::after { background: var(--ink); }
      hover-open on the others; the suppressed wrap re-arms the moment focus
      moves, so keyboard and pointer handoff stays a clean one-panel relay.
      Scoped to the containers that hold adjacent wrapped triggers; the guard
-     keys on focus-visible inside a wrap, so plain mouse clicks (no panel
+     keys on the component-owned focus state, so plain mouse clicks (no panel
      held open) never suppress anything. */
-  :is(.lr-row-group, .lr-pawn-detail, .lr-entry-actions):has(.lr-comic-tip-wrap:has(:focus-visible))
-    .lr-comic-tip-wrap:not(:has(:focus-visible)):hover .lr-comic-tip {
+  :is(.lr-row-group, .lr-pawn-detail, .lr-entry-actions):has(.lr-comic-tip-wrap.is-focus-open)
+    .lr-comic-tip-wrap:not(.is-focus-open).is-hover-open .lr-comic-tip {
     opacity: 0;
     transition-delay: 0s;
   }
-  :is(.lr-row-group, .lr-pawn-detail, .lr-entry-actions):has(.lr-comic-tip-wrap:has(:focus-visible))
-    .lr-comic-tip-wrap:not(:has(:focus-visible)):hover::before {
+  :is(.lr-row-group, .lr-pawn-detail, .lr-entry-actions):has(.lr-comic-tip-wrap.is-focus-open)
+    .lr-comic-tip-wrap:not(.is-focus-open).is-hover-open::before {
     opacity: 0;
     transition-delay: 0s;
   }
 }
 
 /* channels 2+3: keyboard focus-visible and touch long-press */
-.lr-comic-tip-wrap:has(:focus-visible) .lr-comic-tip,
+.lr-comic-tip-wrap.is-focus-open .lr-comic-tip,
 .lr-comic-tip-wrap.is-tip-open .lr-comic-tip {
   opacity: 1;
   transform: translateX(-50%) translateY(0);
   transition-delay: .12s;
 }
-.lr-comic-tip-wrap:has(:focus-visible) .lr-comic-tip *,
+.lr-comic-tip-wrap.is-focus-open .lr-comic-tip *,
 .lr-comic-tip-wrap.is-tip-open .lr-comic-tip * {
   animation-play-state: running !important;
 }
-.lr-comic-tip-wrap:has(:focus-visible) .lr-comic-tip.is-below,
+.lr-comic-tip-wrap.is-focus-open .lr-comic-tip.is-below,
 .lr-comic-tip-wrap.is-tip-open .lr-comic-tip.is-below { transform: translateX(-50%) translateY(0); }
-.lr-comic-tip-wrap:has(:focus-visible) .lr-comic-tip.is-start,
-.lr-comic-tip-wrap:has(:focus-visible) .lr-comic-tip.is-end,
+.lr-comic-tip-wrap.is-focus-open .lr-comic-tip.is-start,
+.lr-comic-tip-wrap.is-focus-open .lr-comic-tip.is-end,
 .lr-comic-tip-wrap.is-tip-open .lr-comic-tip.is-start,
 .lr-comic-tip-wrap.is-tip-open .lr-comic-tip.is-end { transform: translateX(0) translateY(0); }
-.lr-comic-tip-wrap:has(:focus-visible)::before,
+.lr-comic-tip-wrap.is-focus-open::before,
 .lr-comic-tip-wrap.is-tip-open::before {
   opacity: 1;
   transform: rotate(45deg) scale(1);
diff --git a/src/client/ui/copy.ts b/src/client/ui/copy.ts
index cb1dd4f..8d99c60 100644
--- a/src/client/ui/copy.ts
+++ b/src/client/ui/copy.ts
@@ -89,11 +89,15 @@ if (typeof window !== "undefined") {
 // Non-React setter (used by the mode pill and by tests).
 export const setCopy = commit;
 
+export function isCopyKey(value: string): value is CopyKey {
+  return Object.prototype.hasOwnProperty.call(catalogs.zh, value);
+}
+
 export function t(lang: Lang, key: CopyKey, vars?: Record<string, string>): string {
   let value = catalogs[lang][key];
   if (vars) {
     for (const [name, replacement] of Object.entries(vars)) {
-      value = value.replace(`{${name}}`, replacement);
+      value = value.replace(`{${name}}`, () => replacement);
     }
   }
   return value;
diff --git a/src/client/ui/icons.tsx b/src/client/ui/icons.tsx
index 2f16326..656a210 100644
--- a/src/client/ui/icons.tsx
+++ b/src/client/ui/icons.tsx
@@ -18,6 +18,7 @@ const PATHS: Record<string, { body: ReactNode; solid?: boolean }> = {
   pause: { solid: true, body: (<><rect pathLength={1} x="6" y="4" width="4.2" height="16" rx="1.2"/><rect pathLength={1} x="13.8" y="4" width="4.2" height="16" rx="1.2"/></>) },
   stop: { solid: true, body: (<><rect pathLength={1} x="6" y="6" width="12" height="12" rx="2"/></>) },
   share: { body: (<><rect pathLength={1} x="2" y="4" width="20" height="13" rx="2"/><path pathLength={1} d="M12 17v-7m0 0-3 3m3-3 3 3"/><path pathLength={1} d="M8 21h8"/></>) },
+  switchSource: { body: (<><rect pathLength={1} x="2" y="4" width="20" height="14" rx="2"/><path pathLength={1} d="M7 9h9m0 0-2.5-2.5M16 9l-2.5 2.5M17 13H8m0 0 2.5-2.5M8 13l2.5 2.5"/><path pathLength={1} d="M8 22h8M12 18v4"/></>) },
   hash: { body: (<><path pathLength={1} d="M9 3 7 21M17 3l-2 18M4 8h17M3 16h17"/></>) },
   users: { body: (<><circle pathLength={1} cx="9" cy="8" r="3.5"/><path pathLength={1} d="M2.5 20c.8-3.2 3.4-5 6.5-5s5.7 1.8 6.5 5"/><circle pathLength={1} cx="17" cy="9" r="2.5"/><path pathLength={1} d="M16.2 15.2c2.5.4 4.6 1.8 5.3 4.8"/></>) },
   network: { body: (<><rect pathLength={1} x="9" y="2" width="6" height="6" rx="1.5"/><rect pathLength={1} x="2" y="16" width="6" height="6" rx="1.5"/><rect pathLength={1} x="16" y="16" width="6" height="6" rx="1.5"/><path pathLength={1} d="M12 8v3.5M12 11.5 5.5 16M12 11.5l6.5 4.5"/></>) },
diff --git a/src/client/webrtc/stats.ts b/src/client/webrtc/stats.ts
index 3008199..53fc09c 100644
--- a/src/client/webrtc/stats.ts
+++ b/src/client/webrtc/stats.ts
@@ -80,6 +80,7 @@ export function collectNativeSenderQualityFromReport(
   accumulator: NativeSenderQualityAccumulator,
 ): Pick<
   ConnectionMetrics,
+  | "sampleTimestampMs"
   | "nativeEdgeQualityState"
   | "qualityLimitationReason"
   | "sampleWindowMs"
@@ -145,7 +146,14 @@ export function collectNativeSenderQualityFromReport(
     } else {
       accumulator.previousByStatsId.delete(record.id);
     }
-    return { state, reason, windowMs, intervalFramesEncoded, bitrateKbps };
+    return {
+      timestamp,
+      state,
+      reason,
+      windowMs,
+      intervalFramesEncoded,
+      bitrateKbps,
+    };
   });
   const bitrateKbps =
     samples.length > 0 && samples.every((sample) => sample.bitrateKbps !== null)
@@ -156,11 +164,13 @@ export function collectNativeSenderQualityFromReport(
     samples.some(
       (sample) =>
         sample.state === "unknown" ||
+        sample.timestamp === null ||
         sample.windowMs === null ||
         sample.intervalFramesEncoded === null,
     )
   ) {
     return {
+      sampleTimestampMs: null,
       nativeEdgeQualityState: "unknown",
       qualityLimitationReason: null,
       sampleWindowMs: null,
@@ -170,6 +180,7 @@ export function collectNativeSenderQualityFromReport(
   }
   const degraded = samples.filter((sample) => sample.state === "degraded");
   return {
+    sampleTimestampMs: Math.min(...samples.map((sample) => sample.timestamp!)),
     nativeEdgeQualityState: degraded.length > 0 ? "degraded" : "healthy",
     qualityLimitationReason:
       degraded.some((sample) => sample.reason === "bandwidth")
diff --git a/src/client/webrtc/viewer-peer.ts b/src/client/webrtc/viewer-peer.ts
index 541def9..b385f30 100644
--- a/src/client/webrtc/viewer-peer.ts
+++ b/src/client/webrtc/viewer-peer.ts
@@ -309,6 +309,7 @@ export class ViewerPeer {
       })) {
         throw new Error(say("viewer.msg.serverError"));
       }
+      this.clearRecoveryTimer();
       this.offerRecoveryAttempts = 0;
       this.scheduleInitialConnectionDeadline(connection, connectionId);
     } catch (error) {
diff --git a/src/server/hybrid-media-router.ts b/src/server/hybrid-media-router.ts
index 70443f6..8b421a5 100644
--- a/src/server/hybrid-media-router.ts
+++ b/src/server/hybrid-media-router.ts
@@ -611,18 +611,20 @@ export class HybridMediaRouter {
       const childToParent =
         input.sourcePeerId === operation.childPeerId &&
         input.targetPeerId === current.tuple.parentPeerId;
-      return Boolean(
-        parent &&
-          child &&
-          parent.sessionId === (parentToChild ? input.sourceSessionId : input.targetSessionId) &&
-          child.sessionId === (childToParent ? input.sourceSessionId : input.targetSessionId) &&
-          input.connectionId === current.connectionId &&
-          (input.signalKind === "candidate" ||
-            (parentToChild && input.descriptionType === "offer") ||
-            (childToParent && input.descriptionType === "answer")),
-      )
-        ? "probe"
-        : false;
+      if (parentToChild || childToParent) {
+        return Boolean(
+          parent &&
+            child &&
+            parent.sessionId === (parentToChild ? input.sourceSessionId : input.targetSessionId) &&
+            child.sessionId === (childToParent ? input.sourceSessionId : input.targetSessionId) &&
+            input.connectionId === current.connectionId &&
+            (input.signalKind === "candidate" ||
+              (parentToChild && input.descriptionType === "offer") ||
+              (childToParent && input.descriptionType === "answer")),
+        )
+          ? "probe"
+          : false;
+      }
     }
 
     const childPeerId = this.childForPair(snapshot, input.sourcePeerId, input.targetPeerId);
diff --git a/src/server/room-route-controller.ts b/src/server/room-route-controller.ts
index 8190c23..3c4e9cf 100644
--- a/src/server/room-route-controller.ts
+++ b/src/server/room-route-controller.ts
@@ -884,6 +884,7 @@ export class RoomRouteController<Resource = unknown> {
     }
     publication.physicalActive = false;
     publication.usable = false;
+    this.hostPublication = null;
     this.clearSfuQuality();
     this.revision = this.allocateRevision();
     if (this.operation) this.operation.baseRevision = this.revision;
@@ -3843,9 +3844,11 @@ export class RoomRouteController<Resource = unknown> {
       edge.usable = false;
     }
     if (edge.kind === "sfu" && !this.hasSfuSubscribers() && this.hostPublication) {
-      if (this.hostPublication.physicalActive) released.push(this.hostPublication.resource);
-      this.hostPublication.physicalActive = false;
-      this.hostPublication.usable = false;
+      const publication = this.hostPublication;
+      if (publication.physicalActive) released.push(publication.resource);
+      publication.physicalActive = false;
+      publication.usable = false;
+      this.hostPublication = null;
     }
     return true;
   }
diff --git a/src/server/room-store.ts b/src/server/room-store.ts
index 1ad7301..080a8be 100644
--- a/src/server/room-store.ts
+++ b/src/server/room-store.ts
@@ -427,7 +427,10 @@ export class RoomStore {
       expectedSalt,
       mayConnect,
     );
-    if (derived.kind !== "value") {
+    if (derived.kind === "busy") {
+      throw new RoomStoreError("ROOM_BUSY");
+    }
+    if (derived.kind === "cancelled") {
       throw new RoomStoreError("INVALID_TOKEN");
     }
     const matches = timingSafeEqual(derived.value, expectedVerifier);
diff --git a/tests/copy.test.ts b/tests/copy.test.ts
index 87c1078..5950952 100644
--- a/tests/copy.test.ts
+++ b/tests/copy.test.ts
@@ -2,6 +2,7 @@ import { afterEach, describe, expect, it, vi } from "vitest";
 
 import {
   getTitleFrames,
+  isCopyKey,
   say,
   setCopy,
   t,
@@ -20,6 +21,8 @@ describe("copy catalog", () => {
     expect(t("en", "join.title")).toBe("Join a room");
     expect(t("zh", "host.advanced.route.peerOnly")).toBe("隐私模式");
     expect(t("en", "host.advanced.route.peerOnly")).toBe("Privacy mode");
+    expect(isCopyKey("viewer.reconnect")).toBe(true);
+    expect(isCopyKey("Reconnect media")).toBe(false);
   });
 
   it("interpolates variables", () => {
@@ -27,6 +30,7 @@ describe("copy catalog", () => {
     expect(t("en", "host.onlineCount", { n: "4", max: "20" })).toBe(
       "4 / 20 online",
     );
+    expect(t("zh", "viewer.title", { name: "$&" })).toBe("$& 的屏幕");
   });
 
   it("keeps zh and en key sets identical", () => {
diff --git a/tests/hybrid-media-router.test.ts b/tests/hybrid-media-router.test.ts
index a7813a2..22f3b68 100644
--- a/tests/hybrid-media-router.test.ts
+++ b/tests/hybrid-media-router.test.ts
@@ -656,6 +656,93 @@ describe("HybridMediaRouter v9 runtime", () => {
     }
   });
 
+  it("keeps committed-edge signaling authorized during another Peer candidate", async () => {
+    const { store, sent, router } = harness(2);
+    try {
+      const room = await store.createRoom();
+      const host = connectHost(store, room);
+      complete(router, host);
+
+      const roots = [
+        connectViewer(store, room, "stable-root-a"),
+        connectViewer(store, room, "stable-root-b"),
+      ];
+      for (const root of roots) {
+        complete(router, root);
+        await vi.waitFor(() => expect(preparedFor(sent, root.sessionId)).toBeDefined());
+        const prepared = preparedFor(sent, root.sessionId)!;
+        router.handleRouteReady(root, {
+          type: "route-ready",
+          revision: prepared.revision,
+          phase: "prepare",
+        });
+        router.setViewerRelayCapacity(root, 1);
+      }
+
+      const candidateChild = connectViewer(store, room, "candidate-child");
+      complete(router, candidateChild);
+      const prepared = await vi.waitFor(() => {
+        const update = preparedFor(sent, candidateChild.sessionId);
+        expect(update?.assignment.upstream.kind).toBe("peer");
+        return update!;
+      });
+      const candidateParentPeerId =
+        prepared.assignment.upstream.kind === "peer"
+          ? prepared.assignment.upstream.peerId
+          : "";
+      const candidateParent = roots.find(
+        (root) => root.peerId === candidateParentPeerId,
+      )!;
+      const activeParentEdge = router.resolveActiveViewerMediaEdge(
+        room.roomId,
+        candidateParent.peerId,
+      )!;
+
+      expect(
+        router.peerSignalAuthorization({
+          roomId: room.roomId,
+          sourcePeerId: host.peerId,
+          sourceSessionId: host.sessionId,
+          targetPeerId: candidateParent.peerId,
+          targetSessionId: candidateParent.sessionId,
+          connectionId: activeParentEdge.connectionId,
+          signalKind: "description",
+          descriptionType: "offer",
+        }),
+      ).toBe(true);
+      expect(
+        router.peerSignalAuthorization({
+          roomId: room.roomId,
+          sourcePeerId: candidateParent.peerId,
+          sourceSessionId: candidateParent.sessionId,
+          targetPeerId: candidateChild.peerId,
+          targetSessionId: candidateChild.sessionId,
+          connectionId: prepared.candidate.connectionId,
+          signalKind: "description",
+          descriptionType: "offer",
+        }),
+      ).toBe("probe");
+
+      const unrelatedRoot = roots.find(
+        (root) => root.peerId !== candidateParent.peerId,
+      )!;
+      expect(
+        router.peerSignalAuthorization({
+          roomId: room.roomId,
+          sourcePeerId: unrelatedRoot.peerId,
+          sourceSessionId: unrelatedRoot.sessionId,
+          targetPeerId: candidateChild.peerId,
+          targetSessionId: candidateChild.sessionId,
+          connectionId: prepared.candidate.connectionId,
+          signalKind: "description",
+          descriptionType: "offer",
+        }),
+      ).toBeUndefined();
+    } finally {
+      await router.close();
+    }
+  });
+
   it("commits P2P quality convergence after client relative approval", async () => {
     const { store, sent, router } = harness(2);
     try {
diff --git a/tests/living-components.test.ts b/tests/living-components.test.ts
index f78d16c..c763307 100644
--- a/tests/living-components.test.ts
+++ b/tests/living-components.test.ts
@@ -2,10 +2,8 @@ import { createElement } from "react";
 import { renderToStaticMarkup } from "react-dom/server";
 import { afterEach, describe, expect, it } from "vitest";
 
-import {
-  Couch,
-  pawnColor,
-} from "../src/client/components/living/Couch.tsx";
+import { Couch } from "../src/client/components/living/Couch.tsx";
+import { participantColor } from "../src/client/components/living/participant-color.ts";
 import {
   BrandLoader,
   BrandMark,
@@ -15,9 +13,9 @@ import { ComicTooltip } from "../src/client/components/living/ComicTooltip.tsx";
 import { HintComic } from "../src/client/components/living/hints/index.tsx";
 import { StageOverlay } from "../src/client/components/living/Stage.tsx";
 import { ViewerOverview } from "../src/client/components/living/ViewerOverview.tsx";
-import { NameTag } from "../src/client/components/living/primitives.tsx";
+import { Btn, NameTag } from "../src/client/components/living/primitives.tsx";
 import { EMPTY_METRICS } from "../src/client/types.ts";
-import { setCopy } from "../src/client/ui/copy.ts";
+import { setCopy, t } from "../src/client/ui/copy.ts";
 
 describe("living-room presentation", () => {
   afterEach(() => setCopy({ lang: "zh", vis: false }));
@@ -97,11 +95,13 @@ describe("living-room presentation", () => {
 
   it("keeps the current display name visible in visual mode", () => {
     setCopy({ lang: "en", vis: true });
+    const identity = "viewer-name-tag";
     const html = renderToStaticMarkup(
-      createElement(NameTag, { name: "TNT" }),
+      createElement(NameTag, { name: "TNT", identity }),
     );
 
     expect(html).toContain(">TNT<");
+    expect(html).toContain(participantColor(identity));
     expect(html).not.toContain("visually-hidden");
   });
 
@@ -121,6 +121,27 @@ describe("living-room presentation", () => {
     expect(html).not.toContain('viewBox="0 0 320 96"');
   });
 
+  it("keeps a hint-wrapped disabled control explainable by keyboard", () => {
+    setCopy({ lang: "en", vis: true });
+    const html = renderToStaticMarkup(
+      createElement(
+        ComicTooltip,
+        {
+          kind: "hint-join-go",
+          children: createElement(Btn, {
+            icon: "refresh",
+            title: "viewer.reconnect",
+            disabled: true,
+          }),
+        },
+      ),
+    );
+
+    expect(html).toContain('class="lr-comic-tip-wrap is-disabled-trigger"');
+    expect(html).toContain('tabindex="0"');
+    expect(html).toContain(`aria-label="${t("en", "viewer.reconnect")}"`);
+  });
+
   it("animates the private-room hint around its door and lock", () => {
     const html = renderToStaticMarkup(
       createElement(HintComic, { kind: "hint-policy-private", size: 240 }),
@@ -133,6 +154,14 @@ describe("living-room presentation", () => {
     expect(html).toContain("vlsPrivLock");
   });
 
+  it("keeps the Host-offline comic free of the waiting-room moon", () => {
+    const html = renderToStaticMarkup(
+      createElement(Comic, { kind: "host-offline", theme: "stage" }),
+    );
+
+    expect(html).not.toContain("M229 39.5a8.5");
+  });
+
   it("keeps every crowded and relay Viewer name visible in visual mode", () => {
     setCopy({ lang: "en", vis: true });
     const html = renderToStaticMarkup(
@@ -152,12 +181,13 @@ describe("living-room presentation", () => {
     expect(html).toContain(
       '<span class="lr-pawn-name">Relay Viewer With A Full Name</span>',
     );
+    expect(html).toContain('title="Relay Viewer With A Full Name"');
     expect(html).not.toContain("max-width:72px");
   });
 
   it("derives every participant color only from the peer identity", () => {
     const peerId = "viewer-stable-identity";
-    const color = pawnColor(peerId);
+    const color = participantColor(peerId);
     const html = renderToStaticMarkup(
       createElement(Couch, {
         entries: [
@@ -171,7 +201,7 @@ describe("living-room presentation", () => {
       }),
     );
 
-    expect(pawnColor(peerId)).toBe(color);
+    expect(participantColor(peerId)).toBe(color);
     expect(html).toContain(color);
     expect(html).not.toContain("var(--you)");
   });
@@ -217,4 +247,27 @@ describe("living-room presentation", () => {
     expect(html).toContain("18 ms");
     expect(html).toContain("Bob");
   });
+
+  it("uses route glyphs without visible route text in visual mode", () => {
+    setCopy({ lang: "en", vis: true });
+    const html = renderToStaticMarkup(
+      createElement(ViewerOverview, {
+        entries: [
+          {
+            key: "viewer-p2p",
+            name: "Alice",
+            connected: true,
+            statusLabel: "Connected",
+            route: "p2p",
+            metrics: null,
+          },
+        ],
+        selectedKey: null,
+        onSelect: () => undefined,
+      }),
+    );
+
+    expect(html).not.toContain("<b>P2P</b>");
+    expect(html).toContain(t("en", "state.route.p2p"));
+  });
 });
diff --git a/tests/metric-cells.test.ts b/tests/metric-cells.test.ts
index 16ea134..c67747c 100644
--- a/tests/metric-cells.test.ts
+++ b/tests/metric-cells.test.ts
@@ -1,15 +1,16 @@
 import { createElement } from "react";
 import { renderToStaticMarkup } from "react-dom/server";
-import { describe, expect, it } from "vitest";
+import { afterEach, describe, expect, it } from "vitest";
 
 import { MetricCells } from "../src/client/components/living/Metrics.tsx";
-import { setCopy } from "../src/client/ui/copy.ts";
+import { setCopy, t } from "../src/client/ui/copy.ts";
 import {
   EMPTY_METRICS,
   type ConnectionMetrics,
 } from "../src/client/types.ts";
 
 setCopy({ lang: "zh", vis: false });
+afterEach(() => setCopy({ lang: "zh", vis: false }));
 
 const metrics = {
   ...EMPTY_METRICS,
@@ -44,6 +45,24 @@ const metrics = {
 } satisfies ConnectionMetrics;
 
 describe("MetricCells progressive disclosure", () => {
+  it("keeps visual metric names available to assistive technology", () => {
+    setCopy({ lang: "en", vis: true });
+    const html = renderToStaticMarkup(
+      createElement(MetricCells, {
+        metrics,
+        direction: "receive",
+        expanded: true,
+        onToggle: () => undefined,
+      }),
+    );
+
+    for (const key of ["stats.resolution", "stats.fps", "stats.loss", "stats.rtt"] as const) {
+      expect(html).toContain(
+        `<span class="visually-hidden">${t("en", key)}</span>`,
+      );
+    }
+  });
+
   it("keeps one-glance picture results above an accessible detail expansion", () => {
     const collapsed = renderToStaticMarkup(
       createElement(MetricCells, {
diff --git a/tests/release-app-recovery.sh b/tests/release-app-recovery.sh
new file mode 100644
index 0000000..22a7d80
--- /dev/null
+++ b/tests/release-app-recovery.sh
@@ -0,0 +1,132 @@
+#!/bin/bash
+set -euo pipefail
+
+repo_root="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")/.." && pwd)"
+release_script="$repo_root/deploy/release-app.sh"
+
+extract_function() {
+  awk -v name="$1" '
+    $0 == name "() {" { capture = 1 }
+    capture { print }
+    capture && $0 == "}" { exit }
+  ' "$release_script"
+}
+
+eval "$(extract_function cleanup_stage)"
+if grep -q '^cleanup_release() {' "$release_script"; then
+  eval "$(extract_function cleanup_release)"
+fi
+eval "$(extract_function wait_for_health)"
+eval "$(extract_function recover)"
+
+test_root="$(mktemp -d)"
+trap 'rm -rf --one-file-system -- "$test_root"' EXIT
+release_root="$test_root/releases"
+current="$test_root/current"
+release_id='abcdef0'
+old_release="$release_root/old"
+release="$release_root/$release_id"
+stage=''
+mkdir -p "$old_release"
+
+systemctl_start_fails=0
+rm_release_fails=0
+systemctl() {
+  if [ "${1:-}" = 'start' ] && [ "$systemctl_start_fails" -eq 1 ]; then
+    return 1
+  fi
+  if [ "${1:-}" = 'show' ]; then
+    printf 'active\n'
+  fi
+  return 0
+}
+wait_for_health() { return 0; }
+
+rm() {
+  local path="${!#}"
+  if [ "$rm_release_fails" -eq 1 ] && [ "$path" = "$release" ]; then
+    return 1
+  fi
+  command rm "$@"
+}
+
+readlink() {
+  local path="${!#}"
+  if [ "$path" = "$current" ] && [ -f "$current" ]; then
+    cat "$current"
+    return
+  fi
+  command readlink "$@"
+}
+
+ln() {
+  if [ "${1:-}" = '-s' ]; then
+    printf '%s\n' "$2" > "$3"
+    return
+  fi
+  command ln "$@"
+}
+
+mv() {
+  if [ "${1:-}" = '-Tf' ]; then
+    command mv -f -- "$2" "$3"
+    return
+  fi
+  command mv "$@"
+}
+
+set_current() {
+  printf '%s\n' "$1" > "$current"
+}
+
+reset_release() {
+  rm -rf --one-file-system -- "$release"
+  rm -rf --one-file-system -- "$current"
+  mkdir -p "$release"
+  set_current "$old_release"
+  stage=''
+  cutover_started=0
+  systemctl_start_fails=0
+}
+
+run_recover() {
+  local expected="$1" code
+  set +e
+  (recover 37) >/dev/null 2>&1
+  code=$?
+  set -e
+  test "$code" -eq "$expected"
+}
+
+reset_release
+release_owned=1
+run_recover 37
+test ! -e "$release"
+
+reset_release
+release_owned=0
+run_recover 37
+test -d "$release"
+
+reset_release
+release_owned=1
+rm_release_fails=1
+run_recover 90
+test -d "$release"
+rm_release_fails=0
+
+reset_release
+release_owned=1
+cutover_started=1
+set_current "$release"
+run_recover 37
+test "$(readlink -f -- "$current")" = "$old_release"
+test ! -e "$release"
+
+reset_release
+release_owned=1
+cutover_started=1
+systemctl_start_fails=1
+set_current "$release"
+run_recover 90
+test -d "$release"
diff --git a/tests/release-app.test.ts b/tests/release-app.test.ts
new file mode 100644
index 0000000..2d26518
--- /dev/null
+++ b/tests/release-app.test.ts
@@ -0,0 +1,24 @@
+import { spawnSync } from "node:child_process";
+import { existsSync } from "node:fs";
+import { fileURLToPath } from "node:url";
+import { describe, expect, it } from "vitest";
+
+const bash =
+  process.platform === "win32"
+    ? [
+        "C:\\Program Files\\Git\\bin\\bash.exe",
+        "C:\\Program Files\\Git\\usr\\bin\\bash.exe",
+      ].find(existsSync)
+    : "/bin/bash";
+const testWithBash = bash && existsSync(bash) ? it : it.skip;
+
+describe("application release recovery", () => {
+  testWithBash("removes only the unactivated release owned by this run", () => {
+    const script = fileURLToPath(
+      new URL("./release-app-recovery.sh", import.meta.url),
+    );
+    const result = spawnSync(bash!, [script], { encoding: "utf8" });
+
+    expect(result.status, `${result.stdout}\n${result.stderr}`).toBe(0);
+  });
+});
diff --git a/tests/room-route-controller.test.ts b/tests/room-route-controller.test.ts
index bebd421..3f53682 100644
--- a/tests/room-route-controller.test.ts
+++ b/tests/room-route-controller.test.ts
@@ -3668,6 +3668,52 @@ describe("RoomRouteController", () => {
     expect(bootstrap.reconcile(4).operation?.childPeerId).toBe(B);
   });
 
+  it("reopens SFU bootstrap after the physical publication retires", () => {
+    const routes = controller(2, { sfuEnabled: true });
+    addViewer(routes, A, 0);
+    routes.hydrateHostPublication("retired_publication", "publication_resource");
+    routes.hydrateEdge(A, {
+      kind: "sfu",
+      publicationGeneration: "retired_publication",
+      transport: "sfu",
+      connectionId: "a_from_sfu",
+      usable: true,
+      physicalActive: true,
+      resource: "a_subscription",
+    });
+
+    const publication = routes.snapshot().hostPublication!;
+    expect(
+      routes.retireHostPublication({
+        hostSessionId: publication.hostSessionId,
+        routeRevision: routes.snapshot().revision,
+        generation: publication.generation,
+        connectionId: publication.connectionId,
+      }),
+    ).toEqual(expect.arrayContaining(["a_subscription", "publication_resource"]));
+    expect(routes.snapshot().hostPublication).toBeNull();
+
+    for (const [peerId, connectionId] of [
+      [B, "b_from_host"],
+      [C, "c_from_host"],
+    ] as const) {
+      addViewer(routes, peerId, 0);
+      routes.hydrateEdge(peerId, peerEdge(HOST, connectionId));
+    }
+    expect(routes.reconcile(1)).toMatchObject({
+      failedPeerIds: [],
+      operation: {
+        demandPeerId: A,
+        reason: "sfu-bootstrap",
+        candidates: [
+          {
+            tuple: { kind: "sfu", publication: "create" },
+          },
+        ],
+      },
+    });
+  });
+
   it("binds reserve and skip results to the exact candidate cursor", () => {
     const reserve = controller(2);
     addViewer(reserve, A, 2);
diff --git a/tests/room-store.test.ts b/tests/room-store.test.ts
index e8a201e..a14600d 100644
--- a/tests/room-store.test.ts
+++ b/tests/room-store.test.ts
@@ -350,6 +350,22 @@ describe("RoomStore", () => {
     );
   });
 
+  it("keeps password-gate saturation distinct from invalid credentials", async () => {
+    const { store: roomStore } = store();
+    const room = await roomStore.createRoom("private", "room-password");
+
+    await expect(
+      withSaturatedPasswordGate(roomStore, () =>
+        roomStore.connectViewerWithPassword({
+          roomId: room.roomId,
+          password: "room-password",
+          clientId: "busy-password-client",
+          sessionId: "busy-password-session",
+        }),
+      ),
+    ).rejects.toEqual(new RoomStoreError("ROOM_BUSY"));
+  });
+
   it("keeps room replacement and password updates unchanged when busy", async () => {
     const { store: roomStore } = store({
       maxRooms: 3,
@@ -439,7 +455,14 @@ describe("RoomStore", () => {
           result.status === "rejected" &&
           result.reason.code === "INVALID_TOKEN",
       ),
-    ).toHaveLength(38);
+    ).toHaveLength(16);
+    expect(
+      results.filter(
+        (result) =>
+          result.status === "rejected" &&
+          result.reason.code === "ROOM_BUSY",
+      ),
+    ).toHaveLength(22);
   });
 
   it("rotates and revokes Viewer grants without changing code entry", async () => {
diff --git a/tests/route-transition.test.ts b/tests/route-transition.test.ts
index 138e1f4..e166264 100644
--- a/tests/route-transition.test.ts
+++ b/tests/route-transition.test.ts
@@ -587,6 +587,48 @@ describe("minimal route transition contracts", () => {
     expect(reconciledChildren.at(-1)).toEqual(["retained-child"]);
   });
 
+  it("rebuilds a failed Host SFU publisher while sharing is paused", async () => {
+    const messages: ClientMessage[] = [];
+    const publishers: ReturnType<typeof createFakePublisher>[] = [];
+    const disconnects: Array<() => void> = [];
+    const route = new HostSfuRoute({
+      getStream: () => ({}) as MediaStream,
+      getProfile: () => QUALITY_PROFILES["720p30"],
+      getVideoCodec: () => "vp8",
+      reconcileChildren: () => undefined,
+      send: (message) => {
+        messages.push(message);
+        return true;
+      },
+      createPublisher: (onDisconnected) => {
+        disconnects.push(onDisconnected);
+        const publisher = createFakePublisher(
+          [],
+          `publisher-${publishers.length + 1}`,
+        );
+        publishers.push(publisher);
+        return publisher;
+      },
+    });
+
+    await route.acceptAndWait({
+      revision: 1,
+      phase: "active",
+      assignment: hostAssignment("publication-paused"),
+    });
+    await route.acceptConfig(sfuConfig(1));
+    route.setPaused(true);
+    disconnects[0]!();
+    expect(messages).toContainEqual({ type: "refresh-sfu", revision: 1 });
+
+    await route.acceptConfig({ ...sfuConfig(1), token: "recovery-token" });
+    expect(publishers).toHaveLength(2);
+    expect(publishers[1]!.setPaused).toHaveBeenCalledWith(true);
+
+    route.setPaused(false);
+    expect(publishers[1]!.setPaused).toHaveBeenLastCalledWith(false);
+  });
+
   it("does not activate a fresh SFU publisher after its exact route becomes stale", async () => {
     let releaseFreshPublisher!: () => void;
     const freshPublisherGate = new Promise<void>((resolve) => {
@@ -1242,6 +1284,51 @@ describe("minimal route transition contracts", () => {
     expect(messages.filter((message) => message.type === "route-ready")).toEqual([]);
   });
 
+  it("rebuilds a failed Viewer SFU subscriber while sharing is paused", async () => {
+    const messages: ClientMessage[] = [];
+    const streams: MediaStream[] = [];
+    const subscribers: ReturnType<typeof createFakeSubscriber>[] = [];
+    const route = new ViewerSfuRoute("viewer_12345678", {
+      activatePeer: () => true,
+      reconcileSfuChildren: () => undefined,
+      onSfuStream: (stream) => streams.push(stream),
+      send: (message) => {
+        messages.push(message);
+        return true;
+      },
+      createSubscriber: (events) => {
+        const subscriber = createFakeSubscriber(
+          events,
+          [],
+          `subscriber-${subscribers.length + 1}`,
+        );
+        subscribers.push(subscriber);
+        return subscriber;
+      },
+    });
+
+    route.accept({
+      revision: 7,
+      phase: "active",
+      assignment: viewerSfuAssignment(),
+    });
+    await route.acceptConfig(sfuConfig(7));
+    subscribers[0]!.events.onStream({} as MediaStream);
+    subscribers[0]!.events.onFirstDecodedFrame();
+    await vi.waitFor(() => expect(streams).toHaveLength(1));
+
+    route.setPaused(true);
+    subscribers[0]!.events.onDisconnected();
+    expect(messages).toContainEqual({ type: "refresh-sfu", revision: 7 });
+
+    await route.acceptConfig({ ...sfuConfig(7), token: "recovery-token" });
+    expect(subscribers).toHaveLength(2);
+    expect(subscribers[1]!.armDecodedFrameProof).not.toHaveBeenCalled();
+
+    route.setPaused(false);
+    expect(subscribers[1]!.armDecodedFrameProof).toHaveBeenCalledOnce();
+  });
+
 
   it("retires only an unreferenced paused Viewer SFU slot", async () => {
     const messages: ClientMessage[] = [];
diff --git a/tests/route-tree.test.ts b/tests/route-tree.test.ts
index b254ff8..f9ca3f3 100644
--- a/tests/route-tree.test.ts
+++ b/tests/route-tree.test.ts
@@ -3,6 +3,7 @@ import { renderToStaticMarkup } from "react-dom/server";
 import { afterEach, describe, expect, it } from "vitest";
 
 import { RouteTree } from "../src/client/components/living/RouteTree.tsx";
+import { participantColor } from "../src/client/components/living/participant-color.ts";
 import { topologyLayoutForViewport } from "../src/client/components/living/route-tree-layout.ts";
 import { labelParticipantSnapshot } from "../src/client/lib/viewer-presence.ts";
 import { setCopy } from "../src/client/ui/copy.ts";
@@ -195,6 +196,20 @@ describe("RouteTree", () => {
     expect(html).not.toContain("<title");
   });
 
+  it("uses the Host identity color in the topology", () => {
+    const hostPeerId = "host-color-identity";
+    const html = renderToStaticMarkup(
+      createElement(RouteTree, {
+        hostPeerId,
+        hostLabel: "Host",
+        viewers: [],
+      }),
+    );
+
+    expect(html).toContain(participantColor(hostPeerId));
+    expect(html).not.toContain('fill="var(--couch)"');
+  });
+
   it("fits a one-Viewer topology inside a narrow container", () => {
     const hostName = "这是一个合法的二十四字中文分享者显示名称甲乙丙丁";
     const { host, viewers } = labelParticipantSnapshot([
diff --git a/tests/sfu-client.test.ts b/tests/sfu-client.test.ts
index 79fe3ce..950b0ec 100644
--- a/tests/sfu-client.test.ts
+++ b/tests/sfu-client.test.ts
@@ -1,6 +1,7 @@
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 
 import { QUALITY_PROFILES } from "../src/client/media/quality.ts";
+import { sfuPublisherQualityEvidenceFromMetrics } from "../src/client/media/sender-quality-evidence.ts";
 import { SfuPublisher } from "../src/client/sfu/publisher.ts";
 import { SfuSubscriber } from "../src/client/sfu/subscriber.ts";
 import type { ConnectionMetrics } from "../src/client/types.ts";
@@ -546,8 +547,26 @@ describe("SfuPublisher", () => {
 
     await vi.advanceTimersByTimeAsync(2_000);
     expect(updates.at(-1)?.bitrateKbps).toBeNull();
+    expect(
+      sfuPublisherQualityEvidenceFromMetrics(
+        updates.at(-1)!,
+        7,
+        "simulcast_publication_12345678",
+      ),
+    ).toMatchObject({ state: "unknown", sampleTimestampMs: null });
     await vi.advanceTimersByTimeAsync(2_000);
     expect(updates.at(-1)?.bitrateKbps).toBe(2_400);
+    expect(updates.at(-1)?.sampleTimestampMs).toBe(3_000);
+    expect(
+      sfuPublisherQualityEvidenceFromMetrics(
+        updates.at(-1)!,
+        7,
+        "simulcast_publication_12345678",
+      ),
+    ).toMatchObject({
+      state: "healthy",
+      sampleTimestampMs: 3_000,
+    });
   });
 
   it("enables balanced SFU adaptation after startup frames", async () => {
@@ -1182,6 +1201,42 @@ describe("SfuPublisher", () => {
     expect(publisher.getQualityWarning()).toBeNull();
   });
 
+  it("reconciles pause state onto a video clone committed after reconnect", async () => {
+    const publisher = new SfuPublisher();
+    const sourceVideo = track("video", "video-pause-race");
+    await publisher.connect(connection);
+    await publisher.activate(stream(sourceVideo), qualityProfile);
+    publisher.setPaused(true);
+    sourceVideo.enabled = false;
+
+    const room = livekit.state.rooms[0];
+    await room.localParticipant.republishForReconnect();
+    const publication = room.localParticipant.getTrackPublication(
+      Track.Source.ScreenShare,
+    )!;
+    const replaceGate = deferred();
+    publication.track.replaceTrack.mockImplementationOnce(
+      async (nextTrack: MediaStreamTrack) => {
+        await replaceGate.promise;
+        publication.track.currentTrack = nextTrack;
+        publication.track.sender.track = nextTrack;
+      },
+    );
+
+    room.emit(RoomEvent.Reconnected);
+    await vi.waitFor(() =>
+      expect(publication.track.replaceTrack).toHaveBeenCalledOnce(),
+    );
+    sourceVideo.enabled = true;
+    publisher.setPaused(false);
+    replaceGate.resolve();
+
+    await vi.waitFor(() =>
+      expect(publication.track.currentTrack).not.toBe(publication.rawTrack),
+    );
+    expect(publication.track.currentTrack.enabled).toBe(true);
+  });
+
   it("retains video sender readback across a signal-only reconnect", async () => {
     const publisher = new SfuPublisher();
     await publisher.connect(connection);
diff --git a/tests/video-frame-proof.test.ts b/tests/video-frame-proof.test.ts
index a6bf2ae..a9a40b1 100644
--- a/tests/video-frame-proof.test.ts
+++ b/tests/video-frame-proof.test.ts
@@ -57,7 +57,32 @@ describe("composited video frame proof", () => {
     expect(onFrame).not.toHaveBeenCalled();
 
     cancel();
-    expect(video.cancelVideoFrameCallback).toHaveBeenCalledWith(7);
+    expect(video.cancelVideoFrameCallback).not.toHaveBeenCalled();
+  });
+
+  it("keeps observing when the first composited callback arrives before readiness", () => {
+    const stream = {} as MediaStream;
+    const video = fakeVideo(stream);
+    const callbacks: Array<() => void> = [];
+    video.requestVideoFrameCallback = (callback) => {
+      callbacks.push(callback);
+      return callbacks.length;
+    };
+    const onFrame = vi.fn();
+    const cancel = observeCompositedVideoFrame(
+      video as unknown as HTMLVideoElement,
+      stream,
+      onFrame,
+    );
+
+    callbacks[0]!();
+    expect(onFrame).not.toHaveBeenCalled();
+    expect(callbacks).toHaveLength(2);
+
+    video.readyState = 2;
+    callbacks[1]!();
+    expect(onFrame).toHaveBeenCalledOnce();
+    cancel();
   });
 
   it("uses decoded progress plus readiness in the event fallback", () => {
diff --git a/tests/viewer-peer-generation.test.ts b/tests/viewer-peer-generation.test.ts
index f5c57bb..b65eb73 100644
--- a/tests/viewer-peer-generation.test.ts
+++ b/tests/viewer-peer-generation.test.ts
@@ -629,6 +629,31 @@ describe("ViewerPeer connection generations", () => {
     peer.dispose();
   });
 
+  it("retires the recovery deadline when a rebuilt connection is answered", async () => {
+    const exhausted: string[] = [];
+    const peer = new ViewerPeer(
+      { iceServers: [] },
+      {
+        sendSignal: () => true,
+        sendRestartRequest: () => true,
+        onStream: () => undefined,
+        onUpdate: () => undefined,
+        onRecoveryExhausted: (_peerId, connectionId) => {
+          exhausted.push(connectionId);
+          return true;
+        },
+      },
+    );
+
+    await peer.acceptSignal("relay-parent", offer("connection-before-rebuild"));
+    expect(peer.requestRecovery(true)).toBe(true);
+    await peer.acceptSignal("relay-parent", offer("connection-after-rebuild"));
+
+    expect([...timeoutDelays.values()]).toEqual([15_000]);
+    expect(exhausted).toEqual([]);
+    peer.dispose();
+  });
+
   it("does not send an old answer or candidate after replacing the connection", async () => {
     const oldLocalDescription = createDeferred<void>();
     FakePeerConnection.plans.push({
diff --git a/tests/viewer-playback.test.ts b/tests/viewer-playback.test.ts
new file mode 100644
index 0000000..1929d7f
--- /dev/null
+++ b/tests/viewer-playback.test.ts
@@ -0,0 +1,21 @@
+import { describe, expect, it, vi } from "vitest";
+
+import { prepareViewerPlayback } from "../src/client/media/viewer-playback.ts";
+
+describe("Viewer playback binding", () => {
+  it("arms every media generation even when the MediaStream identity is reused", () => {
+    const stream = {} as MediaStream;
+    const video = {
+      srcObject: null as MediaProvider | null,
+      pause: vi.fn(),
+    };
+
+    expect(prepareViewerPlayback(video, stream, false)).toBe(true);
+    expect(video.srcObject).toBe(stream);
+    expect(prepareViewerPlayback(video, stream, false)).toBe(true);
+    expect(video.pause).not.toHaveBeenCalled();
+
+    expect(prepareViewerPlayback(video, stream, true)).toBe(false);
+    expect(video.pause).toHaveBeenCalledOnce();
+  });
+});
diff --git a/tests/viewer-presentation.test.ts b/tests/viewer-presentation.test.ts
index 506bcfd..56035ad 100644
--- a/tests/viewer-presentation.test.ts
+++ b/tests/viewer-presentation.test.ts
@@ -46,6 +46,7 @@ describe("Viewer presentation reducer", () => {
     const playing = reduceViewerPresentation(receiving, {
       type: "frame-presented",
       generation: 1,
+      proofEpoch: 0,
       revision: 1,
     });
     expect(deriveViewerPresentation(playing)).toMatchObject({
@@ -134,7 +135,7 @@ describe("Viewer presentation reducer", () => {
       { type: "route", revision: 2, phase: "active", kind: "p2p" },
       { type: "connection", revision: 2, connection: "connected" },
       { type: "media-bound", generation: 4, revision: 2 },
-      { type: "frame-presented", generation: 4, revision: 2 },
+      { type: "frame-presented", generation: 4, proofEpoch: 0, revision: 2 },
     );
     const rebased = reduceViewerPresentation(playing, {
       type: "route",
@@ -146,6 +147,7 @@ describe("Viewer presentation reducer", () => {
     expect(rebased.media).toEqual({
       generation: 4,
       boundAtRevision: 2,
+      proofEpoch: 0,
       framePresented: true,
     });
     expect(rebased.connection).toBe("connected");
@@ -180,7 +182,7 @@ describe("Viewer presentation reducer", () => {
       { type: "host", host: "online" },
       { type: "route", revision: 5, phase: "active", kind: "p2p" },
       { type: "media-bound", generation: 5, revision: 5 },
-      { type: "frame-presented", generation: 5, revision: 5 },
+      { type: "frame-presented", generation: 5, proofEpoch: 0, revision: 5 },
     );
     const preparing = reduceViewerPresentation(oldMedia, {
       type: "route",
@@ -202,9 +204,8 @@ describe("Viewer presentation reducer", () => {
 
     expect(staleAutoplay).toMatchObject({
       autoplayBlockedGeneration: 5,
-      failure: "AUTOPLAY_BLOCKED",
     });
-    expect(staleFailure).toMatchObject({ failure: "PLAYBACK_FAILED" });
+    expect(staleFailure).toMatchObject({ playbackFailedGeneration: 5 });
     expect(deriveViewerPresentation(preparing)).toMatchObject({
       stage: "playing",
       overlay: "none",
@@ -227,7 +228,6 @@ describe("Viewer presentation reducer", () => {
     });
 
     expect(preparing.autoplayBlockedGeneration).toBe(5);
-    expect(preparing.failure).toBe("AUTOPLAY_BLOCKED");
     expect(deriveViewerPresentation(preparing)).toMatchObject({
       stage: "receiving",
     });
@@ -239,7 +239,7 @@ describe("Viewer presentation reducer", () => {
       { type: "host", host: "online" },
       { type: "route", revision: 5, phase: "active", kind: "p2p" },
       { type: "media-bound", generation: 5, revision: 5 },
-      { type: "frame-presented", generation: 5, revision: 5 },
+      { type: "frame-presented", generation: 5, proofEpoch: 0, revision: 5 },
     );
     const recovering = reduceViewerPresentation(oldFrame, {
       type: "route",
@@ -257,6 +257,7 @@ describe("Viewer presentation reducer", () => {
     const continuingProof = reduceViewerPresentation(recovering, {
       type: "frame-presented",
       generation: 5,
+      proofEpoch: 0,
       revision: 5,
     });
     expect(continuingProof).toMatchObject({
@@ -271,6 +272,7 @@ describe("Viewer presentation reducer", () => {
     const proven = reduceViewerPresentation(rebound, {
       type: "frame-presented",
       generation: 6,
+      proofEpoch: 0,
       revision: 6,
     });
     expect(deriveViewerPresentation(proven)).toMatchObject({
@@ -287,7 +289,7 @@ describe("Viewer presentation reducer", () => {
       { type: "host", host: "online" },
       { type: "route", revision: 0, phase: "active", kind: "p2p" },
       { type: "media-bound", generation: 1, revision: 0 },
-      { type: "frame-presented", generation: 1, revision: 0 },
+      { type: "frame-presented", generation: 1, proofEpoch: 0, revision: 0 },
       { type: "signal", signal: "reconnecting" },
     );
     expect(deriveViewerPresentation(state)).toMatchObject({
@@ -310,6 +312,7 @@ describe("Viewer presentation reducer", () => {
     const resumed = reduceViewerPresentation(recovering, {
       type: "frame-presented",
       generation: 2,
+      proofEpoch: 0,
       revision: 3,
     });
     expect(resumed.connection).toBe("connected");
@@ -327,7 +330,7 @@ describe("Viewer presentation reducer", () => {
       { type: "host", host: "online" },
       { type: "route", revision: 3, phase: "active", kind: "sfu" },
       { type: "media-bound", generation: 2, revision: 3 },
-      { type: "frame-presented", generation: 2, revision: 3 },
+      { type: "frame-presented", generation: 2, proofEpoch: 0, revision: 3 },
       { type: "route-status", revision: 3, state: "failed" },
     );
     const recovering = reduceViewerPresentation(failed, {
@@ -339,13 +342,13 @@ describe("Viewer presentation reducer", () => {
     expect(recovering).toMatchObject({
       connection: "reconnecting",
       routeStatus: null,
-      failure: null,
       media: { generation: 2, framePresented: false },
     });
 
     const resumed = reduceViewerPresentation(recovering, {
       type: "frame-presented",
       generation: 2,
+      proofEpoch: 1,
       revision: 3,
     });
     expect(resumed.connection).toBe("connected");
@@ -355,6 +358,43 @@ describe("Viewer presentation reducer", () => {
     });
   });
 
+  it("re-proves committed media across background route attempts", () => {
+    const playing = apply(
+      { type: "access", access: "ready" },
+      { type: "signal", signal: "connected" },
+      { type: "host", host: "online" },
+      { type: "route", revision: 74, phase: "active", kind: "sfu" },
+      { type: "media-bound", generation: 9, revision: 74 },
+      { type: "frame-presented", generation: 9, proofEpoch: 0, revision: 74 },
+      { type: "frame-proof-reset", generation: 9, revision: 74 },
+      { type: "route", revision: 75, phase: "prepare", kind: "p2p" },
+      { type: "route", revision: 76, phase: "active", kind: "sfu" },
+      { type: "route", revision: 77, phase: "prepare", kind: "p2p" },
+    );
+
+    expect(
+      reduceViewerPresentation(playing, {
+        type: "frame-presented",
+        generation: 9,
+        proofEpoch: 0,
+        revision: 74,
+      }),
+    ).toBe(playing);
+
+    const reproved = reduceViewerPresentation(playing, {
+      type: "frame-presented",
+      generation: 9,
+      proofEpoch: 1,
+      revision: 74,
+    });
+    expect(deriveViewerPresentation(reproved)).toMatchObject({
+      stage: "playing",
+      overlay: "none",
+      hasCurrentFrame: true,
+      hasRetainedFrame: false,
+    });
+  });
+
   it("keeps a browser playback failure across unrelated active authority", () => {
     const failed = apply(
       { type: "access", access: "ready" },
@@ -370,10 +410,55 @@ describe("Viewer presentation reducer", () => {
       kind: "sfu",
     });
 
-    expect(rebased.failure).toBe("PLAYBACK_FAILED");
+    expect(rebased.playbackFailedGeneration).toBe(2);
     expect(deriveViewerPresentation(rebased).stage).toBe("playback-failed");
   });
 
+  it("keeps Host, route, and playback facts orthogonal", () => {
+    const playbackFailed = apply(
+      { type: "access", access: "ready" },
+      { type: "host", host: "online" },
+      { type: "route", revision: 3, phase: "active", kind: "sfu" },
+      { type: "media-bound", generation: 2, revision: 3 },
+      { type: "playback-failed", generation: 2, revision: 3 },
+      { type: "host", host: "offline" },
+      { type: "host", host: "online" },
+    );
+    expect(playbackFailed.playbackFailedGeneration).toBe(2);
+    expect(deriveViewerPresentation(playbackFailed).stage).toBe(
+      "playback-failed",
+    );
+
+    const routeFailed = applyFrom(
+      playbackFailed,
+      { type: "route-status", revision: 3, state: "failed" },
+      { type: "host", host: "offline" },
+      { type: "host", host: "online" },
+    );
+    expect(routeFailed.routeStatus).toEqual({ revision: 3, state: "failed" });
+    expect(deriveViewerPresentation(routeFailed).stage).toBe("route-failed");
+  });
+
+  it("does not retain a frame that remains current while a route waits", () => {
+    const waiting = apply(
+      { type: "access", access: "ready" },
+      { type: "host", host: "online" },
+      { type: "route", revision: 3, phase: "active", kind: "sfu" },
+      { type: "media-bound", generation: 2, revision: 3 },
+      { type: "frame-presented", generation: 2, proofEpoch: 0, revision: 3 },
+      { type: "route-status", revision: 4, state: "waiting" },
+    );
+
+    expect(waiting.media?.framePresented).toBe(true);
+    expect(waiting.retainedFrame).toBe(false);
+    expect(deriveViewerPresentation(waiting)).toMatchObject({
+      stage: "playing",
+      overlay: "none",
+      hasCurrentFrame: true,
+      hasRetainedFrame: false,
+    });
+  });
+
   it("keeps a healthy Host-offline frame but invalidates it on upstream failure", () => {
     const offlineWithMedia = apply(
       { type: "access", access: "ready" },
@@ -381,7 +466,7 @@ describe("Viewer presentation reducer", () => {
       { type: "host", host: "online" },
       { type: "route", revision: 3, phase: "active", kind: "p2p" },
       { type: "media-bound", generation: 2, revision: 3 },
-      { type: "frame-presented", generation: 2, revision: 3 },
+      { type: "frame-presented", generation: 2, proofEpoch: 0, revision: 3 },
       { type: "host", host: "offline" },
     );
     expect(deriveViewerPresentation(offlineWithMedia)).toMatchObject({
@@ -392,13 +477,15 @@ describe("Viewer presentation reducer", () => {
     });
     expect(
       reduceViewerPresentation(offlineWithMedia, {
-        type: "media-invalidated",
-        revision: 2,
+        type: "frame-proof-reset",
+        generation: 1,
+        revision: 3,
       }),
     ).toBe(offlineWithMedia);
 
     const failed = reduceViewerPresentation(offlineWithMedia, {
-      type: "media-invalidated",
+      type: "frame-proof-reset",
+      generation: 2,
       revision: 3,
     });
     expect(deriveViewerPresentation(failed)).toMatchObject({
@@ -410,6 +497,53 @@ describe("Viewer presentation reducer", () => {
     });
   });
 
+  it("lets current media prove a frame while Host signaling is offline", () => {
+    const offlineBeforeFirstFrame = apply(
+      { type: "access", access: "ready" },
+      { type: "signal", signal: "connected" },
+      { type: "host", host: "online" },
+      { type: "route", revision: 3, phase: "active", kind: "p2p" },
+      { type: "media-bound", generation: 2, revision: 3 },
+      { type: "host", host: "offline" },
+    );
+    const lateFrame = reduceViewerPresentation(offlineBeforeFirstFrame, {
+      type: "frame-presented",
+      generation: 2,
+      proofEpoch: 0,
+      revision: 3,
+    });
+
+    expect(deriveViewerPresentation(lateFrame)).toMatchObject({
+      stage: "playing",
+      overlay: "none",
+      hasCurrentFrame: true,
+      noticeKey: "viewer.notice.hostOffline",
+    });
+
+    const previouslyPlaying = apply(
+      { type: "access", access: "ready" },
+      { type: "signal", signal: "connected" },
+      { type: "host", host: "online" },
+      { type: "route", revision: 3, phase: "active", kind: "p2p" },
+      { type: "media-bound", generation: 2, revision: 3 },
+      { type: "frame-presented", generation: 2, proofEpoch: 0, revision: 3 },
+      { type: "host", host: "offline" },
+      { type: "frame-proof-reset", generation: 2, revision: 3 },
+    );
+    const reproved = reduceViewerPresentation(previouslyPlaying, {
+      type: "frame-presented",
+      generation: 2,
+      proofEpoch: 1,
+      revision: 3,
+    });
+    expect(deriveViewerPresentation(reproved)).toMatchObject({
+      stage: "playing",
+      overlay: "none",
+      hasCurrentFrame: true,
+      noticeKey: "viewer.notice.hostOffline",
+    });
+  });
+
   it("retains the current frame while signaling reconnects", () => {
     const reconnecting = apply(
       { type: "access", access: "ready" },
@@ -417,7 +551,7 @@ describe("Viewer presentation reducer", () => {
       { type: "host", host: "online" },
       { type: "route", revision: 3, phase: "active", kind: "p2p" },
       { type: "media-bound", generation: 2, revision: 3 },
-      { type: "frame-presented", generation: 2, revision: 3 },
+      { type: "frame-presented", generation: 2, proofEpoch: 0, revision: 3 },
       { type: "signal", signal: "reconnecting" },
     );
 
@@ -436,7 +570,7 @@ describe("Viewer presentation reducer", () => {
       { type: "host", host: "online" },
       { type: "route", revision: 3, phase: "active", kind: "p2p" },
       { type: "media-bound", generation: 2, revision: 3 },
-      { type: "frame-presented", generation: 2, revision: 3 },
+      { type: "frame-presented", generation: 2, proofEpoch: 0, revision: 3 },
     );
     const reset = reduceViewerPresentation(playing, {
       type: "frame-proof-reset",
@@ -468,6 +602,7 @@ describe("Viewer presentation reducer", () => {
       reduceViewerPresentation(reset, {
         type: "frame-presented",
         generation: 2,
+        proofEpoch: 1,
         revision: 3,
       }).media?.framePresented,
     ).toBe(true);
@@ -480,7 +615,7 @@ describe("Viewer presentation reducer", () => {
       { type: "host", host: "online" },
       { type: "route", revision: 4, phase: "active", kind: "sfu" },
       { type: "media-bound", generation: 3, revision: 4 },
-      { type: "frame-presented", generation: 3, revision: 4 },
+      { type: "frame-presented", generation: 3, proofEpoch: 0, revision: 4 },
     );
     const failed = reduceViewerPresentation(playing, {
       type: "route-status",
@@ -501,6 +636,7 @@ describe("Viewer presentation reducer", () => {
     const lateFrame = reduceViewerPresentation(failed, {
       type: "frame-presented",
       generation: 3,
+      proofEpoch: 0,
       revision: 4,
     });
     expect(lateFrame).toBe(failed);
@@ -518,19 +654,19 @@ describe("Viewer presentation reducer", () => {
       kind: "sfu",
     });
     expect(restored.routeStatus).toBeNull();
-    expect(restored.failure).toBeNull();
     expect(
       reduceViewerPresentation(restored, {
         type: "frame-presented",
         generation: 3,
+        proofEpoch: 1,
         revision: 4,
       }).media?.framePresented,
     ).toBe(true);
 
     const localFailure = reduceViewerPresentation(playing, {
-      type: "failure",
-      failure: "ROUTE_EXHAUSTED",
+      type: "route-status",
       revision: 4,
+      state: "failed",
     });
     expect(
       reduceViewerPresentation(localFailure, {
@@ -599,6 +735,26 @@ describe("Viewer presentation reducer", () => {
     expect(viewerFailureFromServerCode("ROOM_ACCESS_DENIED")).toBe(
       "ROOM_ACCESS_DENIED",
     );
+    expect(viewerFailureFromServerCode("FORBIDDEN")).toBeNull();
+    expect(viewerFailureFromServerCode("INVALID_MESSAGE")).toBeNull();
+  });
+
+  it("keeps an intentional stop authoritative over the following offline fact", () => {
+    const stopped = apply(
+      { type: "access", access: "ready" },
+      { type: "host", host: "online" },
+      { type: "sharing-stopped" },
+      { type: "host", host: "offline" },
+    );
+
+    expect(stopped).toMatchObject({
+      host: "stopped",
+    });
+    expect(deriveViewerPresentation(stopped)).toMatchObject({
+      stage: "waiting-host",
+      messageKey: "viewer.msg.waitingHost",
+      failureCode: "HOST_STOPPED",
+    });
   });
 
   it("starts a fresh route revision namespace after sharing stops", () => {
@@ -607,7 +763,7 @@ describe("Viewer presentation reducer", () => {
       { type: "host", host: "online" },
       { type: "route", revision: 8, phase: "active", kind: "p2p" },
       { type: "media-bound", generation: 2, revision: 8 },
-      { type: "frame-presented", generation: 2, revision: 8 },
+      { type: "frame-presented", generation: 2, proofEpoch: 0, revision: 8 },
     );
     const stopped = reduceViewerPresentation(previousShare, {
       type: "sharing-stopped",
@@ -619,14 +775,13 @@ describe("Viewer presentation reducer", () => {
       connection: "idle",
       media: null,
       retainedFrame: false,
-      failure: "HOST_STOPPED",
     });
 
     const restarted = applyFrom(stopped,
       { type: "host", host: "online" },
       { type: "route", revision: 1, phase: "prepare", kind: "p2p" },
       { type: "media-bound", generation: 3, revision: 1 },
-      { type: "frame-presented", generation: 3, revision: 1 },
+      { type: "frame-presented", generation: 3, proofEpoch: 0, revision: 1 },
     );
     expect(deriveViewerPresentation(restarted)).toMatchObject({
       stage: "playing",
diff --git a/tests/viewer-quality-evidence.test.ts b/tests/viewer-quality-evidence.test.ts
index ee2b5ab..df0d41b 100644
--- a/tests/viewer-quality-evidence.test.ts
+++ b/tests/viewer-quality-evidence.test.ts
@@ -207,7 +207,7 @@ describe("viewer quality evidence", () => {
     );
     const first = snapshot("connection_first_12345678");
 
-    expect(reporter.offer(first, 0, true)).toBe(false);
+    expect(reporter.offer(first, 0, true)).toBe(true);
     expect(reporter.offer(first, 0, true)).toBe(false);
     now += 2_000;
     expect(
@@ -272,7 +272,7 @@ describe("viewer quality evidence", () => {
         2,
         false,
       ),
-    ).toBe(false);
+    ).toBe(true);
     expect(
       reporter.offer(
         snapshot(
@@ -293,7 +293,7 @@ describe("viewer quality evidence", () => {
         2,
         true,
       ),
-    ).toBe(false);
+    ).toBe(true);
     now += 2_000;
     expect(
       reporter.offer(
@@ -314,6 +314,7 @@ describe("viewer quality evidence", () => {
               revision: message.guard.routeRevision,
               epoch: message.guard.presentationEpoch,
               sequence: message.sequence,
+              diagnostic: message.metrics.freezeCountDelta === null,
             }
           : null,
       ),
@@ -323,34 +324,63 @@ describe("viewer quality evidence", () => {
         revision: 0,
         epoch: 0,
         sequence: 0,
+        diagnostic: true,
+      },
+      {
+        connectionId: "connection_first_12345678",
+        revision: 0,
+        epoch: 0,
+        sequence: 1,
+        diagnostic: false,
       },
       {
         connectionId: "connection_first_12345678",
         revision: 2,
         epoch: 0,
-        sequence: 1,
+        sequence: 2,
+        diagnostic: false,
       },
       {
         connectionId: "connection_second_12345678",
         revision: 2,
         epoch: 0,
         sequence: 0,
+        diagnostic: false,
       },
       {
         connectionId: "connection_second_12345678",
         revision: 2,
         epoch: 1,
         sequence: 0,
+        diagnostic: true,
+      },
+      {
+        connectionId: "connection_second_12345678",
+        revision: 2,
+        epoch: 1,
+        sequence: 1,
+        diagnostic: true,
+      },
+      {
+        connectionId: "connection_second_12345678",
+        revision: 2,
+        epoch: 1,
+        sequence: 2,
+        diagnostic: false,
       },
     ]);
   });
 
   it("reports SFU metrics with the exact route identity", () => {
+    let now = 10_000;
     const sent: ClientMessage[] = [];
-    const reporter = new ViewerQualityEvidenceReporter((message) => {
-      sent.push(message);
-      return true;
-    });
+    const reporter = new ViewerQualityEvidenceReporter(
+      (message) => {
+        sent.push(message);
+        return true;
+      },
+      () => now,
+    );
 
     expect(
       reporter.offerMetrics(
@@ -359,7 +389,8 @@ describe("viewer quality evidence", () => {
         3,
         true,
       ),
-    ).toBe(false);
+    ).toBe(true);
+    now += 2_000;
     expect(
       reporter.offerMetrics(
         "sfu_connection_12345678",
@@ -377,6 +408,17 @@ describe("viewer quality evidence", () => {
           presentationEpoch: 0,
         },
         sequence: 0,
+        metrics: expect.objectContaining({ freezeCountDelta: null }),
+      }),
+      expect.objectContaining({
+        type: "viewer-quality-evidence",
+        guard: {
+          connectionId: "sfu_connection_12345678",
+          routeRevision: 3,
+          presentationEpoch: 0,
+        },
+        sequence: 1,
+        metrics: expect.objectContaining({ freezeCountDelta: 0 }),
       }),
     ]);
   });
@@ -393,7 +435,7 @@ describe("viewer quality evidence", () => {
     );
     const connectionId = "decoded_progress_connection_12345678";
 
-    expect(reporter.offer(snapshot(connectionId), 4, true)).toBe(false);
+    expect(reporter.offer(snapshot(connectionId), 4, true)).toBe(true);
     now += 2_000;
     expect(
       reporter.offer(
@@ -420,7 +462,7 @@ describe("viewer quality evidence", () => {
         4,
         true,
       ),
-    ).toBe(false);
+    ).toBe(true);
     now += 2_000;
     expect(
       reporter.offer(
@@ -436,6 +478,21 @@ describe("viewer quality evidence", () => {
         true,
       ),
     ).toBe(true);
+    now += 2_000;
+    expect(
+      reporter.offer(
+        snapshot(
+          connectionId,
+          receiveMetrics({
+            sampleTimestampMs: 18_000,
+            intervalFreezeCount: 1,
+            intervalFreezeDurationMs: 2_000,
+          }),
+        ),
+        4,
+        true,
+      ),
+    ).toBe(true);
 
     expect(
       sent.flatMap((message) =>
@@ -450,8 +507,11 @@ describe("viewer quality evidence", () => {
           : [],
       ),
     ).toEqual([
-      { epoch: 0, sequence: 0, freezeDurationMs: 0 },
-      { epoch: 0, sequence: 1, freezeDurationMs: 2_000 },
+      { epoch: 0, sequence: 0, freezeDurationMs: null },
+      { epoch: 0, sequence: 1, freezeDurationMs: 0 },
+      { epoch: 1, sequence: 0, freezeDurationMs: null },
+      { epoch: 1, sequence: 1, freezeDurationMs: null },
+      { epoch: 1, sequence: 2, freezeDurationMs: 2_000 },
     ]);
   });