From a7e2dd65909a4a4eab795f86efd12f90a905626a Mon Sep 17 00:00:00 2001
From: crosswk <crosswk@users.noreply.github.com>
Date: Tue, 2 Jun 2026 15:22:30 +0800
Subject: [PATCH] =?UTF-8?q?chore:=20=E6=95=B4=E5=90=88=E5=90=8E=E7=AB=AF?=
 =?UTF-8?q?=E6=9B=B4=E6=96=B0=E4=B8=8E=E6=96=87=E6=A1=A3=EF=BC=8C=E5=87=86?=
 =?UTF-8?q?=E5=A4=87=200.0.4=20=E5=8F=91=E5=B8=83?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

- 后端: ASR 性能优化与热词幻觉修复 (asr.py / main.py)，调整 config.example.yaml vllm_max_model_len
- 补充 docs AI/ASR 服务提供商文档
- 同步客户端原生层(src-tauri)、overlay、recorder 等既有改动
- .gitignore 忽略 we-media/ 运营资料
---
 .gitignore                                    |   2 +
 README.md                                     |   2 +-
 client/src-tauri/src/commands/window.rs       |   7 +
 client/src-tauri/src/main.rs                  |   1 +
 client/src-tauri/src/window/mod.rs            | 123 ++++++++++-
 .../src/features/settings/AppearancePage.tsx  |  59 +++---
 client/src/overlay/main.tsx                   |   9 +
 client/src/pages/About.tsx                    |   2 +-
 client/src/pages/History.tsx                  | 193 +++++++++++++-----
 client/src/services/bridge.ts                 |  21 +-
 client/src/services/recorder.ts               |   5 +
 .../services/recorder/RecorderOrchestrator.ts |   6 +
 .../src/services/webviewKeyboardFallback.ts   |  37 ++++
 docs/SayIt AI 服务提供商.md                   |  83 ++++++++
 docs/SayIt AI 润色供应商配置.md               |   8 +-
 docs/SayIt ASR 服务提供商.md                  |  95 +++++++++
 server/backend/app/asr.py                     | 105 +++++++++-
 server/backend/app/main.py                    |  37 +++-
 server/config.example.yaml                    |   2 +-
 19 files changed, 691 insertions(+), 106 deletions(-)
 create mode 100644 docs/SayIt AI 服务提供商.md
 create mode 100644 docs/SayIt ASR 服务提供商.md

diff --git a/.gitignore b/.gitignore
index 034e5ab..132aa99 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,6 +7,8 @@ config.yaml
 # ── Development-only (not for open source) ──
 dev-docs/
 dev-scripts/
+dev-notes/
+we-media/
 sayit说话波形图效果.html
 
 # ── Server dev artifacts ──
diff --git a/README.md b/README.md
index 130d6b4..818dce7 100644
--- a/README.md
+++ b/README.md
@@ -4,7 +4,7 @@
 
 # SayIt
 
-**开口即成稿 — 用说话代替打字，AI 实时把口语变成书面表达。**
+**随口说，出色写 — 用说话代替打字，AI 实时把口语变成书面表达。**
 
 按下快捷键开始说话，再按一次，润色后的文字自动输入到光标位置。
 
diff --git a/client/src-tauri/src/commands/window.rs b/client/src-tauri/src/commands/window.rs
index 44f6a9f..d99ae8d 100644
--- a/client/src-tauri/src/commands/window.rs
+++ b/client/src-tauri/src/commands/window.rs
@@ -23,3 +23,10 @@ pub async fn update_overlay_state(data: Value, app: AppHandle, window_state: Sta
     window_state.update_overlay_state(&app, &data);
     Ok(())
 }
+
+/// Reported by the overlay webview in response to an `overlay-ping` event.
+/// Used to detect WebView2 unresponsiveness.
+#[tauri::command]
+pub fn overlay_pong(seq: u64) {
+    crate::window::record_overlay_pong(seq);
+}
diff --git a/client/src-tauri/src/main.rs b/client/src-tauri/src/main.rs
index 54c5116..f242419 100644
--- a/client/src-tauri/src/main.rs
+++ b/client/src-tauri/src/main.rs
@@ -302,6 +302,7 @@ fn main() {
             commands::window::show_overlay,
             commands::window::hide_overlay,
             commands::window::update_overlay_state,
+            commands::window::overlay_pong,
             // Paste / Context
             commands::paste::paste_text,
             commands::paste::get_probe_result,
diff --git a/client/src-tauri/src/window/mod.rs b/client/src-tauri/src/window/mod.rs
index b330e5b..74d3e6a 100644
--- a/client/src-tauri/src/window/mod.rs
+++ b/client/src-tauri/src/window/mod.rs
@@ -1,12 +1,30 @@
 use serde_json::Value;
+use std::sync::atomic::{AtomicI64, AtomicU64, Ordering};
 use std::sync::Mutex;
 use tauri::{AppHandle, Emitter, Manager, WebviewUrl, WebviewWindowBuilder};
 
+use crate::commands::system::write_log_line;
+
 const OVERLAY_DEFAULT_BASE_WIDTH: f64 = 360.0;
 const OVERLAY_BASE_HEIGHT: f64 = 56.0;
 const OVERLAY_FALLBACK_WIDTH: f64 = 520.0;
 const OVERLAY_FALLBACK_HEIGHT: f64 = 224.0;
 
+/// Time of last received pong from overlay (epoch millis). 0 = never.
+/// Used to detect WebView2 unresponsiveness in `show_overlay`.
+static LAST_PONG_MS: AtomicI64 = AtomicI64::new(0);
+/// Monotonic id for ping/pong correlation
+static PING_SEQ: AtomicU64 = AtomicU64::new(0);
+
+pub fn record_overlay_pong(_seq: u64) {
+    let now = chrono::Utc::now().timestamp_millis();
+    LAST_PONG_MS.store(now, Ordering::SeqCst);
+}
+
+fn now_ms() -> i64 {
+    chrono::Utc::now().timestamp_millis()
+}
+
 #[derive(Debug, Clone, PartialEq)]
 enum OverlayLayout {
     Base,
@@ -31,25 +49,93 @@ impl WindowState {
         let is_fallback = layout == OverlayLayout::Fallback;
         let base_w = *self.overlay_base_width.lock().unwrap();
 
+        let bounds = calc_overlay_bounds(app, is_fallback, base_w);
+        let (mon_w, mon_h, mon_scale) = monitor_info(app);
+
         if let Some(overlay) = app.get_webview_window("overlay") {
-            let bounds = calc_overlay_bounds(app, is_fallback, base_w);
-            let _ = overlay.set_position(tauri::Position::Logical(tauri::LogicalPosition::new(bounds.0, bounds.1)));
-            let _ = overlay.set_size(tauri::Size::Logical(tauri::LogicalSize::new(bounds.2, bounds.3)));
-            let _ = overlay.show();
-            let _ = overlay.set_always_on_top(true);
+            // ── Diagnostic snapshot before any state change ──
+            let was_visible = overlay.is_visible().unwrap_or(false);
+            let outer_pos = overlay.outer_position()
+                .map(|p| format!("{},{}", p.x, p.y))
+                .unwrap_or_else(|_| "err".to_string());
+            let outer_size = overlay.outer_size()
+                .map(|s| format!("{}x{}", s.width, s.height))
+                .unwrap_or_else(|_| "err".to_string());
+
+            // Probe webview responsiveness — send a ping; pong arrival is logged async.
+            let seq = PING_SEQ.fetch_add(1, Ordering::SeqCst) + 1;
+            let last_pong = LAST_PONG_MS.load(Ordering::SeqCst);
+            let pong_age_ms = if last_pong == 0 { -1 } else { now_ms() - last_pong };
+
+            let ping_emit_err = overlay.emit("overlay-ping", seq).err()
+                .map(|e| format!("{:?}", e));
+
+            write_log_line(&format!(
+                "[overlay-diag] show begin handle=present layout={:?} fallback={} was_visible={} \
+                 outer_pos={} outer_size={} target_bounds={:?} monitor={}x{}@{:.2} \
+                 ping_seq={} last_pong_age_ms={} ping_emit_err={:?}",
+                layout, is_fallback, was_visible,
+                outer_pos, outer_size, bounds, mon_w, mon_h, mon_scale,
+                seq, pong_age_ms, ping_emit_err,
+            ));
+
+            let pos_err = overlay.set_position(tauri::Position::Logical(
+                tauri::LogicalPosition::new(bounds.0, bounds.1)
+            )).err().map(|e| format!("{:?}", e));
+            let size_err = overlay.set_size(tauri::Size::Logical(
+                tauri::LogicalSize::new(bounds.2, bounds.3)
+            )).err().map(|e| format!("{:?}", e));
+            let show_err = overlay.show().err().map(|e| format!("{:?}", e));
+            let aot_err = overlay.set_always_on_top(true).err().map(|e| format!("{:?}", e));
             set_overlay_interactivity(&overlay, is_fallback);
+
+            // Re-snapshot to confirm visibility actually changed
+            let now_visible = overlay.is_visible().unwrap_or(false);
+            let now_outer_pos = overlay.outer_position()
+                .map(|p| format!("{},{}", p.x, p.y))
+                .unwrap_or_else(|_| "err".to_string());
+
+            let any_err = pos_err.is_some() || size_err.is_some()
+                || show_err.is_some() || aot_err.is_some();
+            let level = if any_err { "WARN" } else { "INFO" };
+            write_log_line(&format!(
+                "[overlay-diag] show end [{}] now_visible={} now_outer_pos={} \
+                 pos_err={:?} size_err={:?} show_err={:?} aot_err={:?}",
+                level, now_visible, now_outer_pos,
+                pos_err, size_err, show_err, aot_err,
+            ));
         } else {
+            write_log_line(&format!(
+                "[overlay-diag] show begin handle=MISSING layout={:?} fallback={} \
+                 target_bounds={:?} monitor={}x{}@{:.2} — recreating",
+                layout, is_fallback, bounds, mon_w, mon_h, mon_scale,
+            ));
             self.create_overlay(app, is_fallback, base_w);
         }
     }
 
     pub fn hide_overlay(&self, app: &AppHandle) {
         // Reset to base layout when hiding
-        *self.overlay_layout.lock().unwrap() = OverlayLayout::Base;
+        let prev_layout = {
+            let mut g = self.overlay_layout.lock().unwrap();
+            let prev = g.clone();
+            *g = OverlayLayout::Base;
+            prev
+        };
 
         if let Some(overlay) = app.get_webview_window("overlay") {
             set_overlay_interactivity(&overlay, false);
-            let _ = overlay.hide();
+            let was_visible = overlay.is_visible().unwrap_or(false);
+            let hide_err = overlay.hide().err().map(|e| format!("{:?}", e));
+            write_log_line(&format!(
+                "[overlay-diag] hide prev_layout={:?} was_visible={} hide_err={:?}",
+                prev_layout, was_visible, hide_err,
+            ));
+        } else {
+            write_log_line(&format!(
+                "[overlay-diag] hide handle=MISSING prev_layout={:?}",
+                prev_layout,
+            ));
         }
     }
 
@@ -120,11 +206,21 @@ impl WindowState {
         match builder.build() {
             Ok(overlay) => {
                 set_overlay_interactivity(&overlay, is_fallback);
-                let _ = overlay.show();
+                let show_err = overlay.show().err().map(|e| format!("{:?}", e));
+                let now_visible = overlay.is_visible().unwrap_or(false);
+                write_log_line(&format!(
+                    "[overlay-diag] create_overlay OK is_fallback={} bounds={:?} \
+                     show_err={:?} now_visible={}",
+                    is_fallback, bounds, show_err, now_visible,
+                ));
             }
             Err(e) => {
                 eprintln!("[overlay] create_overlay: FAILED: {}", e);
                 log::error!("Failed to create overlay window: {}", e);
+                write_log_line(&format!(
+                    "[overlay-diag] create_overlay FAILED is_fallback={} bounds={:?} err={:?}",
+                    is_fallback, bounds, e,
+                ));
             }
         }
     }
@@ -134,6 +230,17 @@ fn set_overlay_interactivity(overlay: &tauri::WebviewWindow, interactive: bool)
     let _ = overlay.set_ignore_cursor_events(!interactive);
 }
 
+/// Returns (logical_width, logical_height, scale_factor) of primary monitor.
+fn monitor_info(app: &AppHandle) -> (f64, f64, f64) {
+    if let Some(monitor) = app.primary_monitor().ok().flatten() {
+        let size = monitor.size();
+        let scale = monitor.scale_factor();
+        (size.width as f64 / scale, size.height as f64 / scale, scale)
+    } else {
+        (1920.0, 1080.0, 1.0)
+    }
+}
+
 /// Returns (x, y, width, height)
 fn calc_overlay_bounds(app: &AppHandle, is_fallback: bool, base_w: f64) -> (f64, f64, f64, f64) {
     let (desired_w, desired_h) = if is_fallback {
diff --git a/client/src/features/settings/AppearancePage.tsx b/client/src/features/settings/AppearancePage.tsx
index c579104..31f431b 100644
--- a/client/src/features/settings/AppearancePage.tsx
+++ b/client/src/features/settings/AppearancePage.tsx
@@ -1,12 +1,12 @@
 // 外观设置页面 — 主题 + 悬浮窗样式 + 预览
 
-import { useEffect, useState } from 'react'
+import { useEffect, useRef, useState } from 'react'
 import { Card, CardContent } from '@/components/ui/card'
 import { Switch } from '@/components/ui/switch'
 import { themeList } from '@/themes'
 import { switchTheme, getActiveThemeId } from '@/stores/theme'
 import { getSetting, setSetting } from '@/services/store'
-import { refreshRecorderSettings } from '@/services/recorder'
+import { refreshOverlaySettings } from '@/services/recorder'
 import { OVERLAY_WIDTH_PRESETS, type OverlayWidthPreset } from '@/services/recorder/types'
 import { type OverlayWaveTheme } from './utils'
 
@@ -46,26 +46,37 @@ function getTimerColor(theme: OverlayWaveTheme): string {
 }
 
 function OverlayPreview({ theme, showDuration, barCount }: { theme: OverlayWaveTheme; showDuration: boolean; barCount: number }) {
-  const [bars, setBars] = useState<number[]>(Array.from({ length: barCount }, () => 3))
-
-  useEffect(() => {
-    setBars(Array.from({ length: barCount }, () => 3))
-  }, [barCount])
+  const barRefs = useRef<Array<HTMLDivElement | null>>([])
 
   useEffect(() => {
+    const heights = new Array(barCount).fill(3)
     let running = true
-    const animate = () => {
+    let rafId = 0
+    let lastFrame = 0
+    const FRAME_INTERVAL = 1000 / 30 // 30fps 足够流畅，且不占满主线程
+
+    const animate = (now: number) => {
       if (!running) return
-      setBars((prev) =>
-        prev.map((v) => {
+      if (now - lastFrame >= FRAME_INTERVAL) {
+        lastFrame = now
+        for (let i = 0; i < heights.length; i++) {
           const target = 3 + Math.random() * 15
-          return v + (target - v) * 0.15
-        }),
-      )
-      requestAnimationFrame(animate)
+          heights[i] = heights[i] + (target - heights[i]) * 0.15
+          const el = barRefs.current[i]
+          if (el) {
+            const h = Math.min(18, Math.max(3, heights[i]))
+            el.style.height = `${h}px`
+            el.style.opacity = String(0.7 + (h / 18) * 0.3)
+          }
+        }
+      }
+      rafId = requestAnimationFrame(animate)
+    }
+    rafId = requestAnimationFrame(animate)
+    return () => {
+      running = false
+      cancelAnimationFrame(rafId)
     }
-    requestAnimationFrame(animate)
-    return () => { running = false }
   }, [barCount])
 
   return (
@@ -73,17 +84,17 @@ function OverlayPreview({ theme, showDuration, barCount }: { theme: OverlayWaveT
       {/* 1:1 还原真实悬浮窗样式 */}
       <div className="flex items-center rounded-full border border-slate-600 bg-black px-4 py-2 shadow-[0_6px_16px_rgba(0,0,0,0.35)]">
         <div className="flex items-center gap-[2px]" style={{ height: '20px' }}>
-          {bars.map((height, index) => {
-            const h = Math.min(18, Math.max(3, height))
-            const color = getBarColor(index, bars.length, theme)
+          {Array.from({ length: barCount }, (_, index) => {
+            const color = getBarColor(index, barCount, theme)
             return (
               <div
                 key={index}
+                ref={(el) => { barRefs.current[index] = el }}
                 className="w-[2.5px] rounded-full"
                 style={{
                   backgroundColor: color,
-                  height: `${h}px`,
-                  opacity: 0.7 + (h / 18) * 0.3,
+                  height: '3px',
+                  opacity: 0.7,
                   transition: 'height 50ms ease-out, opacity 50ms ease-out',
                 }}
               />
@@ -130,20 +141,20 @@ export default function AppearancePage() {
   const handleOverlayThemeChange = async (theme: OverlayWaveTheme) => {
     setOverlayWaveTheme(theme)
     await setSetting('overlayWaveTheme', theme)
-    await refreshRecorderSettings()
+    await refreshOverlaySettings()
   }
 
   const handleToggleDuration = async () => {
     const next = !overlayShowDuration
     setOverlayShowDuration(next)
     await setSetting('overlayShowDuration', next)
-    await refreshRecorderSettings()
+    await refreshOverlaySettings()
   }
 
   const handleOverlayWidthChange = async (preset: OverlayWidthPreset) => {
     setOverlayWidth(preset)
     await setSetting('overlayWidth', preset)
-    await refreshRecorderSettings()
+    await refreshOverlaySettings()
   }
 
   return (
diff --git a/client/src/overlay/main.tsx b/client/src/overlay/main.tsx
index 7e8deea..b549f6e 100644
--- a/client/src/overlay/main.tsx
+++ b/client/src/overlay/main.tsx
@@ -1,6 +1,8 @@
 import { startWebviewKeyboardFallback } from '../services/webviewKeyboardFallback'
 import React from 'react'
 import ReactDOM from 'react-dom/client'
+import { listen } from '@tauri-apps/api/event'
+import { invoke } from '@tauri-apps/api/core'
 import Overlay from './Overlay'
 import '../index.css'
 
@@ -11,6 +13,13 @@ document.head.appendChild(style)
 
 void startWebviewKeyboardFallback()
 
+// Health check: respond to ping from main process so it can detect
+// WebView2 unresponsiveness. Bug 003 diagnostic.
+void listen<number>('overlay-ping', (event) => {
+  const seq = typeof event.payload === 'number' ? event.payload : 0
+  void invoke('overlay_pong', { seq }).catch(() => {})
+})
+
 ReactDOM.createRoot(document.getElementById('root')!).render(
   <React.StrictMode>
     <Overlay />
diff --git a/client/src/pages/About.tsx b/client/src/pages/About.tsx
index 09bfb37..9188981 100644
--- a/client/src/pages/About.tsx
+++ b/client/src/pages/About.tsx
@@ -44,7 +44,7 @@ export default function About() {
                 <span className="rounded-full bg-muted/50 px-2.5 py-0.5 text-xs text-muted-foreground">v{currentVersion}</span>
                 <button
                   type="button"
-                  onClick={() => void shellOpen('https://github.com/crosswk/')}
+                  onClick={() => void shellOpen('https://github.com/crosswk/SayIt')}
                   className="flex h-6 w-6 items-center justify-center rounded-full bg-muted/50 text-muted-foreground transition-colors hover:bg-foreground/15 hover:text-foreground"
                   title="GitHub"
                 >
diff --git a/client/src/pages/History.tsx b/client/src/pages/History.tsx
index 028e33a..eaf8697 100644
--- a/client/src/pages/History.tsx
+++ b/client/src/pages/History.tsx
@@ -21,8 +21,17 @@ import {
 import { loadAudioAsDataUrl } from '@/services/audioFileService'
 import { segmentAsrText } from '@/services/textSegmenter'
 import { applyTextReplacements } from '@/services/textReplacement'
-import { getProvider } from '@/services/transcription'
-import { reconnectProvider } from '@/services/recorder'
+import {
+  BUILTIN_SET_WORDS_KEY,
+  BUILTIN_SET_ACTIVE_KEY,
+  CUSTOM_THEMES_KEY,
+  CUSTOM_THEME_ACTIVE_KEY,
+  composeHotwords,
+  normalizeBuiltinSetActive,
+  normalizeBuiltinSetWords,
+  normalizeCustomThemeActive,
+  normalizeCustomThemes,
+} from '@/services/hotwords/model'
 
 const HISTORY_PAGE_SIZE = 100
 
@@ -102,50 +111,146 @@ export default function History() {
     const pcmData = bytes.slice(44)
     const chunk = pcmData.buffer.slice(pcmData.byteOffset, pcmData.byteOffset + pcmData.byteLength)
 
+    // Diagnostic: compute peak amplitude of the PCM data being sent
+    const pcmInt16 = new Int16Array(chunk)
+    let reprocessPeak = 0
+    for (let i = 0; i < pcmInt16.length; i++) {
+      const v = Math.abs(pcmInt16[i])
+      if (v > reprocessPeak) reprocessPeak = v
+    }
+    const reprocessPeakNorm = reprocessPeak / 32768
+    const reprocessDurSec = pcmInt16.length / 16000
+    console.log('[reprocess-diag] PCM stats', {
+      byteLength: chunk.byteLength,
+      samples: pcmInt16.length,
+      durationSec: reprocessDurSec.toFixed(2),
+      peakInt16: reprocessPeak,
+      peakNormalized: reprocessPeakNorm.toFixed(4),
+      wouldBeSilent: reprocessPeakNorm < 0.01,
+    })
+
     const preset = await getActivePreset()
     const aiEnabled = await getSetting('aiEnabled', false)
 
-    // 使用当前 Provider 重新识别
-    const provider = getProvider()
-    let reprocessDone = false
+    // 加载热词
+    let hotwords: string[] = []
+    try {
+      const [rawSetWords, rawSetActive, rawCustomThemes, rawCustomThemeActive] = await Promise.all([
+        getSetting(BUILTIN_SET_WORDS_KEY, {}),
+        getSetting(BUILTIN_SET_ACTIVE_KEY, {}),
+        getSetting(CUSTOM_THEMES_KEY, []),
+        getSetting(CUSTOM_THEME_ACTIVE_KEY, {}),
+      ])
+      const setWords = normalizeBuiltinSetWords(rawSetWords as Record<string, unknown>)
+      const setActive = normalizeBuiltinSetActive(rawSetActive as Record<string, unknown>)
+      const themes = normalizeCustomThemes(rawCustomThemes)
+      const themeActive = normalizeCustomThemeActive(rawCustomThemeActive as Record<string, unknown>, themes)
+      hotwords = composeHotwords([], setWords, setActive, themes, themeActive)
+    } catch { /* ignore */ }
+
+    const clientMeta = await bridge.getClientRuntimeInfo().catch(() => null)
+
+    // 使用独立的 WebSocket 连接进行重新识别，避免干扰 RecorderOrchestrator 的全局连接。
+    const { getWSUrl } = await import('@/services/runtimeConfig')
+    const wsUrl = getWSUrl()
+
     const result = await new Promise<{ asrText: string; llmText: string; asrMs: number; llmMs: number; durationSec: number; asrEngine?: string; asrModel?: string }>((resolve, reject) => {
       const timeout = window.setTimeout(() => {
-        if (!reprocessDone) { reprocessDone = true; provider.disconnect() }
-        reconnectProvider()
+        try { socket.close() } catch { /* ignore */ }
         reject(new Error('重新识别超时'))
-      }, 60000)
+      }, 30_000) // ASR 最多 30 秒
 
-      void provider.connect({
-        onFinal: (r) => {
-          clearTimeout(timeout)
-          reprocessDone = true
-          provider.disconnect()
-          reconnectProvider()
-          resolve(r)
-        },
-        onError: (msg) => {
-          clearTimeout(timeout)
-          if (!reprocessDone) { reprocessDone = true; provider.disconnect() }
-          reconnectProvider()
-          reject(new Error(msg))
-        },
-        onDone: () => {
-          // 如果没有 final 就 done 了，说明没有结果
-        },
-      }).then(async () => {
-        const clientMeta = await bridge.getClientRuntimeInfo().catch(() => null)
-        provider.start({
-          systemPrompt: aiEnabled ? preset.systemPrompt : undefined,
-          disableAi: !aiEnabled,
-          clientMeta,
+      const socket = new WebSocket(wsUrl)
+      socket.binaryType = 'arraybuffer'
+
+      let resolved = false
+
+      socket.onopen = () => {
+        // 发送 start
+        const startMsg: Record<string, unknown> = {
+          cmd: 'start',
           source: 'history_reprocess',
-        })
-        provider.sendAudio(chunk)
-        provider.stop()
-      }).catch((err) => {
-        clearTimeout(timeout)
-        reject(err)
-      })
+          disable_ai: !aiEnabled,
+        }
+        if (aiEnabled && preset.systemPrompt) startMsg.system_prompt = preset.systemPrompt
+        if (clientMeta) {
+          startMsg.client_meta = {
+            user_id: clientMeta.userId,
+            device_id: clientMeta.deviceId,
+            hostname: clientMeta.hostname,
+            client_version: clientMeta.clientVersion,
+            platform: clientMeta.platform,
+            os_version: clientMeta.osVersion,
+            local_ip: clientMeta.localIp,
+            system_locale: clientMeta.systemLocale,
+            cpu_cores: clientMeta.cpuCores,
+            memory_mb: clientMeta.memoryMb,
+          }
+        }
+        if (hotwords.length > 0) startMsg.hotwords = hotwords
+        socket.send(JSON.stringify(startMsg))
+
+        // 分片发送 PCM 数据
+        const CHUNK_SIZE = 32000
+        const totalBytes = chunk.byteLength
+        for (let offset = 0; offset < totalBytes; offset += CHUNK_SIZE) {
+          const end = Math.min(offset + CHUNK_SIZE, totalBytes)
+          socket.send(chunk.slice(offset, end))
+        }
+
+        // 发送 stop
+        socket.send(JSON.stringify({ cmd: 'stop' }))
+      }
+
+      socket.onmessage = (ev) => {
+        if (typeof ev.data !== 'string') return
+        try {
+          const msg = JSON.parse(ev.data)
+          console.log('[reprocess-diag] ws message:', msg.type, msg)
+          if (msg.type === 'final') {
+            resolved = true
+            clearTimeout(timeout)
+            socket.close()
+            resolve({
+              asrText: msg.asr_text || '',
+              llmText: msg.llm_text || '',
+              asrMs: msg.asr_ms || 0,
+              llmMs: msg.llm_ms || 0,
+              durationSec: Number(msg.duration_sec || 0),
+              asrEngine: msg.asr_engine || undefined,
+              asrModel: msg.asr_model || undefined,
+            })
+          } else if (msg.type === 'done' && !resolved) {
+            // 没有 final 就 done 了（后端判定为静音/无结果）
+            resolved = true
+            clearTimeout(timeout)
+            socket.close()
+            resolve({ asrText: '', llmText: '', asrMs: 0, llmMs: 0, durationSec: 0 })
+          } else if (msg.type === 'error') {
+            resolved = true
+            clearTimeout(timeout)
+            socket.close()
+            reject(new Error(msg.message || 'backend error'))
+          }
+        } catch { /* ignore parse errors */ }
+      }
+
+      socket.onerror = () => {
+        if (!resolved) {
+          resolved = true
+          clearTimeout(timeout)
+          reject(new Error('WebSocket 连接错误'))
+        }
+      }
+
+      socket.onclose = (ev) => {
+        console.log('[reprocess-diag] ws closed', { code: ev.code, reason: ev.reason, resolved })
+        if (!resolved) {
+          resolved = true
+          clearTimeout(timeout)
+          reject(new Error(`WebSocket 连接意外关闭 code=${ev.code}`))
+        }
+      }
     })
 
     // 极速模式下 llmText === asrText（后端未经 LLM 处理时直接复制 asrText）
@@ -161,14 +266,10 @@ export default function History() {
       llmMs: result.llmMs,
       charCount: (result.llmText || result.asrText).length,
       isEmpty: !(result.llmText || result.asrText).trim(),
-      workMode: provider.mode,
-      aiProvider: provider.mode === 'server' ? 'server' : undefined,
-      aiModel: provider.mode === 'server' ? undefined : undefined,
-      asrProvider: provider.mode === 'local'
-        ? String(await getSetting('localAsr.modelId', 'sensevoice-small'))
-        : provider.mode === 'cloud_api'
-          ? resolveAsrDisplayModel(String(await getSetting('cloudAsr.provider', '')))
-          : (result.asrModel || result.asrEngine || 'server').replace(/^.*\//, ''),
+      workMode: 'server',
+      aiProvider: 'server',
+      aiModel: undefined,
+      asrProvider: (result.asrModel || result.asrEngine || 'server').replace(/^.*\//, ''),
     })
 
     void loadRecords(debouncedKeyword, visibleCount, favoriteOnly)
diff --git a/client/src/services/bridge.ts b/client/src/services/bridge.ts
index aa7839e..1e64ab3 100644
--- a/client/src/services/bridge.ts
+++ b/client/src/services/bridge.ts
@@ -28,16 +28,31 @@ export function close() {
 
 // ─── Overlay ───
 
+/**
+ * Bug 003 diagnostic helper — log overlay IPC failures to runtime events
+ * (which mirror to sayit.log via appendDebugLog).
+ */
+function logOverlayIpcError(op: string, err: unknown) {
+  try {
+    // Lazy import to avoid circular dep with debugLog
+    void import('./debugLog').then(({ addRuntimeEvent }) => {
+      addRuntimeEvent('error', 'overlay-ipc', `${op} failed`, { error: String(err) })
+    })
+  } catch {
+    console.error(`[overlay-ipc] ${op} failed:`, err)
+  }
+}
+
 export function showOverlay() {
-  invoke('show_overlay')
+  invoke('show_overlay').catch((err) => logOverlayIpcError('show_overlay', err))
 }
 
 export function hideOverlay() {
-  invoke('hide_overlay')
+  invoke('hide_overlay').catch((err) => logOverlayIpcError('hide_overlay', err))
 }
 
 export function updateOverlay(data: unknown) {
-  invoke('update_overlay_state', { data })
+  invoke('update_overlay_state', { data }).catch((err) => logOverlayIpcError('update_overlay_state', err))
 }
 
 // ─── Paste / Context ───
diff --git a/client/src/services/recorder.ts b/client/src/services/recorder.ts
index 6b750ca..0034559 100644
--- a/client/src/services/recorder.ts
+++ b/client/src/services/recorder.ts
@@ -33,6 +33,11 @@ export async function refreshRecorderSettings() {
   await orchestrator.refreshRuntimeSettings()
 }
 
+/** 仅刷新 overlay 显示设置（主题/长度/时长）— 轻量，避免触发全量录音缓存刷新 */
+export async function refreshOverlaySettings() {
+  await orchestrator.refreshOverlaySettings()
+}
+
 /** 工作模式切换后重新连接 */
 export function reconnectProvider() {
   orchestrator.reconnectProvider()
diff --git a/client/src/services/recorder/RecorderOrchestrator.ts b/client/src/services/recorder/RecorderOrchestrator.ts
index 7ca1b24..4539c95 100644
--- a/client/src/services/recorder/RecorderOrchestrator.ts
+++ b/client/src/services/recorder/RecorderOrchestrator.ts
@@ -316,6 +316,12 @@ export class RecorderOrchestrator {
     this.ensureConnection()
   }
 
+  /** 仅刷新 overlay 显示设置（主题/长度/时长），不触碰录音相关缓存。
+   *  用于外观设置页面，避免改个颜色就触发十几个 IPC 调用。 */
+  async refreshOverlaySettings() {
+    await this.overlayService.refreshSettings()
+  }
+
   // ── State machine ──
 
   private transition(to: RecorderState): boolean {
diff --git a/client/src/services/webviewKeyboardFallback.ts b/client/src/services/webviewKeyboardFallback.ts
index 8c2a6d4..80840ee 100644
--- a/client/src/services/webviewKeyboardFallback.ts
+++ b/client/src/services/webviewKeyboardFallback.ts
@@ -44,6 +44,9 @@ const PTT_LAB_VK = 0xA3
 let pttCode = ''
 let pttSetting = ''
 let pttKeyDown = false
+let hfCode = ''
+let hfSetting = ''
+let hfKeyDown = false
 let labKeyDown = false
 let labEnabled = false
 let started = false
@@ -75,6 +78,15 @@ function handleKeyDown(e: KeyboardEvent) {
     return
   }
 
+  // 免提键（HF）：在 keydown 时阻止默认行为，keyup 时触发 toggle
+  if (hfCode && e.code === hfCode && pttCode !== hfCode) {
+    hfKeyDown = true
+    if (isModifierSetting(hfSetting)) {
+      e.preventDefault()
+    }
+    return
+  }
+
   // PTT Lab 键（右 Ctrl）
   if (labEnabled && e.code === PTT_LAB_CODE && !labKeyDown) {
     // 如果 PTT 主键也是右 Ctrl，不重复处理 lab
@@ -112,6 +124,20 @@ function handleKeyUp(e: KeyboardEvent) {
     return
   }
 
+  // 免提键：keyup 时 emit toggle-hands-free
+  if (hfCode && e.code === hfCode && hfKeyDown && pttCode !== hfCode) {
+    hfKeyDown = false
+    if (isModifierSetting(hfSetting)) {
+      e.preventDefault()
+    }
+    console.log('[webview-kb] toggle-hands-free (webview fallback)', { code: e.code, hfSetting })
+    emit('toggle-hands-free', {
+      source: 'webview_fallback',
+      vk: SETTING_TO_VK[hfSetting] || 0,
+    })
+    return
+  }
+
   // PTT Lab 键
   if (labEnabled && e.code === PTT_LAB_CODE && labKeyDown) {
     if (pttCode === PTT_LAB_CODE) return
@@ -137,7 +163,18 @@ export async function refreshPTTSetting() {
   }
   pttCode = SETTING_TO_CODE[pttSetting] || ''
   pttKeyDown = false
+
+  try {
+    const hfSettingVal = await getSetting('shortcutHandsFree', 'AltRight')
+    hfSetting = String(hfSettingVal || 'AltRight')
+  } catch {
+    hfSetting = 'AltRight'
+  }
+  hfCode = SETTING_TO_CODE[hfSetting] || ''
+  hfKeyDown = false
+
   console.log('[webview-kb] PTT setting refreshed:', pttSetting, '→ code:', pttCode)
+  console.log('[webview-kb] HF setting refreshed:', hfSetting, '→ code:', hfCode)
 }
 
 /** PTT Lab 启用/禁用 */
diff --git a/docs/SayIt AI 服务提供商.md b/docs/SayIt AI 服务提供商.md
new file mode 100644
index 0000000..235880d
--- /dev/null
+++ b/docs/SayIt AI 服务提供商.md	
@@ -0,0 +1,83 @@
+# SayIt AI 润色供应商
+
+SayIt 有两个核心功能：语音转文本（ASR）和 AI 文本润色。ASR 部分可以参考 [豆包语音识别凭证获取](豆包ASR凭据获取.md) 和 [阿里云千问语音识别](aliyun.md)。
+
+AI 润色功能可以去除口癖词（嗯、啊、那个）、修正语音识别错误、自动分段排版等，都可以通过 Prompt 自定义控制。
+
+SayIt 已对接国内常用的 AI 服务商（通义千问、DeepSeek、豆包等），同时支持 OpenAI 兼容格式，可以接入其他供应商或第三方中转。
+
+## 1. 最佳实践
+
+**推荐 DeepSeek deepseek-v4-flash 作为默认选择。** 质量最好、价格极低、速度可接受。
+
+DeepSeek V4 Flash（2026 年 4 月发布）是 284B 参数的 MoE 模型，13B 激活参数，支持 1M 上下文。关闭思考模式后速度接近旧版 deepseek-chat，但质量明显更好，价格还更便宜（输入 1 元/百万 Token，输出 2 元/百万 Token）。
+
+如果对延迟极度敏感（需要 <500ms），可以用通义千问 qwen3.6-flash，速度最快但质量略逊。
+
+| 供应商　　　 | 模型　　　　　　　| 短文本　　| 长文本　　 | 每月成本 |
+| --------------| -------------------| -----------| ------------| ----------|
+| **DeepSeek** | deepseek-v4-flash | **803ms** | **2089ms** | ~1.5 元　|
+| 通义千问　　 | qwen3.6-flash　　 | 393ms　　 | 1308ms　　 | ~3.8 元　|
+
+> 月成本按每天 100 次、每次约 100 字估算。V4 Flash 默认开启 thinking，会导致延迟飙升到 2~7 秒。SayIt 已在代码中自动关闭思考模式，无需用户手动配置。
+
+## 2. 如何选择AI模型
+
+- **速度**：总耗时由 TTFT（Time To First Token，首个字生成时间）和 TPS（每秒 Token 数）决定。语音转写场景下，总耗时超过 1~2 秒会有明显等待感。
+- **质量**：能否准确执行 Prompt 指令——去口癖、识别自我修正、格式化列表、纠正专有名词大小写等。
+- **价格**：V4 Flash 的自动 prompt 缓存机制让重复 system prompt 的场景成本极低。
+
+## 3. 实测数据
+
+以下数据是 2026 年 5 月实测的，使用非流式请求（和 SayIt 实际调用方式一致），每条用例跑了 3 次取中位数。
+
+### 速度
+
+| 供应商　 | 模型　　　　　　　　　　　　　| 短文本 | 中等文本 | 长文本（~200字） |
+| ----------| -------------------------------| --------| ----------| ------------------|
+| DeepSeek | deepseek-v4-flash（关闭思考） | 803ms　| 971ms　　| 2089ms　　　　　 |
+| 通义千问 | qwen3.6-flash　　　　　　　　 | 393ms　| 489ms　　| 1308ms　　　　　 |
+
+
+### 质量
+
+两家都能正确去口癖、识别列表结构、纠正专有名词大小写（DeepSeek、ChatGPT、OpenAI 等）。V4 Flash 在专有名词纠正和格式化方面更稳定，输出更简洁。
+
+
+## 4. 关于豆包
+
+豆包的语音识别（ASR）是目前中文场景下最好的，SayIt 推荐使用豆包 ASR。但豆包的 AI 文本模型（lite 和 mini 都测了）延迟极不稳定，中长文本经常超过 10 秒，不适合语音转写的润色场景。建议 ASR 用豆包，AI 润色用 DeepSeek 或通义千问。
+
+## 5. 价格参考
+
+| 供应商　 | 模型　　　　　　　　 | 输入（百万Token） | 输出（百万Token） |
+| ----------| ----------------------| -------------------| -------------------|
+| DeepSeek | deepseek-v4-flash　　| 1 元　　　　　　　| 2 元　　　　　　　|
+| 通义千问 | qwen3.6-flash　　　　| 1.8 元　　　　　　| 10.8 元　　　　　 |
+| 豆包　　 | doubao-seed-2-0-mini | 0.2 元　　　　　　| 2 元　　　　　　　|
+
+
+
+## 6. 配置指南
+
+> 建议直接使用官方 API。第三方中转站延迟普遍更高。
+
+### DeepSeek（推荐）
+
+- API 地址：`https://api.deepseek.com`
+- 模型：`deepseek-v4-flash`
+- 获取 API Key：[platform.deepseek.com](https://platform.deepseek.com/api_keys)
+- **注意**：SayIt 会自动在请求中添加 `thinking: {type: "disabled"}` 关闭思考模式以降低延迟
+![alt text](DeepSeek获取API.png)
+
+### 通义千问
+
+- API 地址：`https://dashscope.aliyuncs.com/compatible-mode`
+- 模型：`qwen3.6-flash`
+- 获取 API Key：[百炼平台](https://bailian.console.aliyun.com/?spm=a2c4g.11186623.0.0.60905ec6iyaRqr&tab=model#/api-key)
+![alt text](百炼获取API.png)
+
+### 豆包（火山方舟）
+- API 地址：`https://ark.cn-beijing.volces.com/api/v3`
+- 模型：`doubao-seed-2-0-mini-260215`
+![alt text](豆包获取API.png)
\ No newline at end of file
diff --git a/docs/SayIt AI 润色供应商配置.md b/docs/SayIt AI 润色供应商配置.md
index 0bbcc38..ab059bb 100644
--- a/docs/SayIt AI 润色供应商配置.md	
+++ b/docs/SayIt AI 润色供应商配置.md	
@@ -12,10 +12,10 @@ AI 润色模型推荐使用 **deepseek-v4-flash** 质量好、价格低、速度
 
 如果对延迟极度敏感（需要 <500ms），可以用通义千问 qwen3.6-flash，速度最快但准确度稍微差点。
 
-| 供应商       | 模型              | 短文本 | 长文本（~200字） | 输入价格         | 输出价格          |
-| ------------ | ----------------- | ------ | ---------------- | ---------------- | ----------------- |
-| **DeepSeek** | deepseek-v4-flash | 803ms  | 2089ms           | 1 元/百万Token   | 2 元/百万Token    |
-| 通义千问     | qwen3.6-flash     | 393ms  | 1308ms           | 1.8 元/百万Token | 10.8 元/百万Token |
+| 供应商　　　 | 模型　　　　　　　| 短文本 | 长文本（~200字） | 输入价格　　　　 | 输出价格　　　　　|
+| --------------| -------------------| --------| ------------------| ------------------| -------------------|
+| **DeepSeek** | deepseek-v4-flash | 803ms　| 2089ms　　　　　 | 1 元/百万Token　 | 2 元/百万Token　　|
+| 通义千问　　 | qwen3.6-flash　　 | 393ms　| 1308ms　　　　　 | 1.8 元/百万Token | 10.8 元/百万Token |
 
 ## 2. 配置指南
 
diff --git a/docs/SayIt ASR 服务提供商.md b/docs/SayIt ASR 服务提供商.md
new file mode 100644
index 0000000..e5ea29f
--- /dev/null
+++ b/docs/SayIt ASR 服务提供商.md	
@@ -0,0 +1,95 @@
+# SayIt ASR 语音识别配置
+
+SayIt 支持三种语音识别模式：
+
+- **云端 API**：调用云服务商的语音识别接口，准确率最高，适合大多数个人用户
+- **本地推理**：使用本地模型离线识别，不需要网络，但准确率和速度不如云端
+- **服务器模式**：自己部署后端服务，适合团队或有定制需求的场景
+
+对个人用户来说，**云端 API 是最推荐的方式**，下面主要介绍这个。
+
+## 1. 最佳实践
+
+中文语音识别准确率最高的是**豆包流式语音识别 2.0**（Seed-ASR-2.0），其次是阿里的**千问 ASR**（qwen3-asr-flash）。
+
+SayIt 对豆包和千问 ASR 都做了流式优化——按住说话时，音频会实时发送给服务端，松手后只需要等待最后一小段音频的处理时间，通常几百毫秒就能拿到结果。
+
+另外 SayIt 还支持**千问 3.5 Omni** 多模态模型，这类模型原生支持音频输入、文本输出，可以在转录的同时执行 Prompt 指令（比如去口癖、翻译等），相当于 ASR + AI 润色一步到位。
+
+| 供应商　　　 | 模型　　　　　　　　　　 | 特点　　　　　　　　　　 | 价格　　　　　　　　　　|
+| --------------| --------------------------| --------------------------| -------------------------|
+| **豆包**　　 | Seed-ASR-2.0　　　　　　 | 中文准确率最高，推荐首选 | 1.00 元/小时　　　　　　|
+| **阿里千问** | qwen3-asr-flash-realtime | 流式识别，速度极快　　　 | 1.19 元/小时　　　　　　|
+| **阿里千问** | qwen3.5-omni-flash　　　 | ASR + AI 一步到位　　　　| 按 Token 计费（见下方） |
+
+
+## 2. 使用豆包语音识别
+
+SayIt 支持使用字节跳动「豆包流式语音识别模型 2.0」作为语音识别引擎。豆包 ASR 是目前中文语音识别准确率最高的模型，推荐使用。
+
+1. 注册 / 登录火山引擎
+
+打开[火山引擎语音服务控制台](https://console.volcengine.com/speech/service/10038)，用手机号注册或登录即可。已有账号的直接登录，没有账号会引导你先注册。
+[图片]
+
+
+2. 完成实名认证
+
+火山引擎的 API 服务需要先做实名认证，没认证的话后面创建应用会卡住。进入[实名认证页面](https://console.volcengine.com/user/authentication/detail/)，按页面提示走完就行。
+[图片]
+
+
+3. 创建应用并获取 APP ID
+
+进入[应用管理页面](https://console.volcengine.com/speech/app1)，点击「创建应用」。填写应用名称和简介（随便写就行），关键一步：一定要勾选「豆包流式语音识别模型 2.0 小时版」，不然后面用不了。
+[图片]
+
+
+4. 获取APP ID 和 Access Token
+
+进入 [API 服务中心页面](https://console.volcengine.com/speech/service/10038)，点击「豆包流式语音识别模型2.0」（配图是旧版界面）。页面上会显示你的 APP ID，鼠标放到 Access Token 上面，点击小眼睛图标，可以看到 Access Token 信息。
+[图片]
+
+记录下来这两个信息填到 SayIt 软件中。选择 语音引擎 - 云 API 模式 - 选择ASR供应商为豆包 ASR，填写凭证信息后可以保存测试。
+[图片]
+
+
+豆包开通试用后，半年内有 20 小时的[免费额度](https://www.volcengine.com/docs/6561/1359369?lang=zh)。超出免费额度后，按量计费：豆包流式语音识别模型 2.0 — 1 元/小时。[后付费价格详情](https://www.volcengine.com/docs/6561/1359370?lang=zh)
+
+
+## 3. 阿里千问 ASR
+
+阿里百炼平台提供了两个语音识别模型，都可以在 SayIt 中使用。
+
+**qwen3-asr-flash / qwen3-asr-flash-realtime**
+
+纯语音识别模型，中文准确率仅次于豆包。有两个版本：
+- **qwen3-asr-flash**：非流式，录完再发，速度也很快
+- **qwen3-asr-flash-realtime**：流式，边录边发，松手后几乎立刻出结果，体验极佳
+
+两者准确率一样，推荐使用流式版本。适合搭配独立的 AI 润色供应商使用（比如通义千问或 DeepSeek 做文本校对）。
+
+**qwen3.5-omni-flash**
+
+多模态模型，可以直接接收音频输入并输出文本。和普通 ASR + AI 润色的两步流程不同，Omni 模型一步完成，可以在 System Prompt 中直接控制输出格式（比如去口癖、翻译、列表排版等）。
+
+适合不想分别配置 ASR 和 AI 润色的用户，配置更简单。
+
+**配置方式**
+
+在 SayIt 设置中选择千问 ASR 系列，需要填写 API Key。
+
+- 获取 API Key：[阿里百炼平台](https://bailian.console.aliyun.com/cn-beijing?tab=model#/api-key)
+
+## 4. 价格
+
+下面是各个模型按需使用的价格参考。
+
+| 模型　　　　　　　　　　　　　　　　　| 价格　　　　　　| 免费额度　　　　　　　 |
+| ---------------------------------------| -----------------| ------------------------|
+| 豆包 Seed-ASR-2.0　　　　　　　　　　 | 1.00 元/小时　　| 20 小时（半年内）　　　|
+| 千问 qwen3-asr-flash（非流式）　　　　| 0.79 元/小时　　| 10 小时（90天内）　　　|
+| 千问 qwen3-asr-flash-realtime（流式） | 1.19 元/小时　　| 10 小时（90天内）　　　|
+| 千问 qwen3.5-omni-flash　　　　　　　 | 约 2.3 元/小时* | 100 万 Token（90天内） |
+
+*Omni 按 Token 计费（每秒音频 ≈ 25 token），2.3 元为粗略估算。详见[千问价格文档](https://help.aliyun.com/zh/model-studio/model-pricing#95f0464a10q5c)。
diff --git a/server/backend/app/asr.py b/server/backend/app/asr.py
index 95c4a53..35b0e78 100644
--- a/server/backend/app/asr.py
+++ b/server/backend/app/asr.py
@@ -61,7 +61,7 @@ class ASREngine:
                 self._model = Qwen3ASRModel.LLM(
                     model=config.asr.model,
                     gpu_memory_utilization=config.asr.vllm_gpu_util,
-                    max_new_tokens=512,
+                    max_new_tokens=2048,
                     max_model_len=config.asr.vllm_max_model_len,
                 )
                 self._backend = "vllm"
@@ -70,7 +70,7 @@ class ASREngine:
                 import torch
                 self._model = Qwen3ASRModel.from_pretrained(
                     config.asr.model, dtype=torch.bfloat16,
-                    device_map=config.asr.device, max_new_tokens=512,
+                    device_map=config.asr.device, max_new_tokens=2048,
                 )
                 self._backend = "transformers"
             logger.info("Qwen3-ASR ready (%s)", self._backend)
@@ -235,15 +235,16 @@ class ASREngine:
                 job_text_parts[idx] = []
                 continue
 
-            if duration <= 120.0:
-                # ≤ 2min: send whole audio, no split — accuracy first.
-                # VAD-based filtering was removed because it aggressively
-                # discards whispered speech (low-energy audio misclassified
-                # as silence), causing severe recognition loss.
+            if duration <= 60.0:
+                # ≤ 1min: send whole audio, no split — accuracy first.
                 segs = [(audio, duration)]
             else:
-                # > 2min: safe split at ≥3s silence gaps
+                # > 1min: safe split at silence gaps
                 segs = self._safe_split(audio)
+                # Merge segments with very low speech ratio into adjacent segments
+                # to avoid batch inference failure from near-silent segments.
+                if len(segs) > 1:
+                    segs = self._merge_silent_segments(segs)
                 logger.info("Safe split %.1fs -> %d segs %s",
                             duration, len(segs), [f"{d:.1f}s" for _, d in segs])
             job_vad_ms[idx] = int((time.monotonic() - vad_t0) * 1000)
@@ -408,7 +409,55 @@ class ASREngine:
             logger.exception("VAD failed")
             return [(audio, len(audio) / 16000.0)] if fallback_to_full else []
 
-    def _safe_split(self, audio: np.ndarray, min_gap: float = 3.0, min_seg: float = 15.0, max_seg: float = 240.0) -> list[tuple[np.ndarray, float]]:
+    def _merge_silent_segments(self, segs: list[tuple[np.ndarray, float]], min_speech_ratio: float = 0.15) -> list[tuple[np.ndarray, float]]:
+        """Merge segments with very low speech ratio into adjacent segments.
+
+        Near-silent segments in a batch can cause vLLM to return empty results
+        for the entire batch. Merging them into neighbors avoids this while
+        preserving any speech content they may contain.
+        """
+        if not self._vad or len(segs) <= 1:
+            return segs
+        import torch
+        # Identify which segments have low speech ratio
+        speech_ok = []
+        for seg_audio, seg_dur in segs:
+            try:
+                res = self._vad.generate(input=torch.tensor(seg_audio, dtype=torch.float32), cache={}, is_final=True)
+                vad_segs = res[0].get("value", []) if res else []
+                speech_time = sum((e - s) for s, e in vad_segs) / 1000.0 if vad_segs else 0
+                speech_ok.append(speech_time / seg_dur >= min_speech_ratio if seg_dur > 0 else True)
+            except Exception:
+                speech_ok.append(True)  # on error, assume it's fine
+
+        if all(speech_ok):
+            return segs
+
+        # Merge low-speech segments into adjacent (prefer previous, fallback to next)
+        merged: list[tuple[np.ndarray, float]] = []
+        i = 0
+        while i < len(segs):
+            if speech_ok[i]:
+                merged.append(segs[i])
+                i += 1
+            else:
+                # Merge into previous segment if available, otherwise next
+                if merged:
+                    prev_audio, prev_dur = merged[-1]
+                    cur_audio, cur_dur = segs[i]
+                    merged[-1] = (np.concatenate([prev_audio, cur_audio]), prev_dur + cur_dur)
+                elif i + 1 < len(segs):
+                    cur_audio, cur_dur = segs[i]
+                    nxt_audio, nxt_dur = segs[i + 1]
+                    merged.append((np.concatenate([cur_audio, nxt_audio]), cur_dur + nxt_dur))
+                    speech_ok[i + 1] = True  # skip next since we consumed it
+                    i += 1
+                else:
+                    merged.append(segs[i])
+                i += 1
+        return merged
+
+    def _safe_split(self, audio: np.ndarray, min_gap: float = 1.0, min_seg: float = 10.0, max_seg: float = 100.0) -> list[tuple[np.ndarray, float]]:
         """Split audio at long silence gaps (≥ min_gap seconds), keeping ALL audio.
 
         Unlike _vad_split which discards silence, this preserves the full audio
@@ -443,7 +492,41 @@ class ASREngine:
                 if all(d >= min_seg for d in seg_durs) and all(d <= max_seg for d in seg_durs):
                     cuts.append(mid)
 
-            if not cuts:
+            if not cuts and dur > 100.0:
+                # Fallback: force split at lowest energy point near ideal boundaries
+                ideal_seg = 60.0  # target segment length
+                n_cuts_needed = max(1, int(dur / ideal_seg) - 1)
+                frame_len = int(0.05 * 16000)  # 50ms frames
+                hop = frame_len // 2
+                n_frames = (len(audio) - frame_len) // hop
+                if n_frames > 0:
+                    energy = np.array([np.sum(audio[i*hop:i*hop+frame_len]**2) for i in range(n_frames)])
+                    # Smooth energy
+                    kernel = np.ones(20) / 20
+                    if len(energy) > len(kernel):
+                        energy = np.convolve(energy, kernel, mode='same')
+                    forced_cuts = []
+                    for c in range(1, n_cuts_needed + 1):
+                        target_time = dur * c / (n_cuts_needed + 1)
+                        # Search window: +/- 10s around target
+                        win_start = max(0, int((target_time - 10) * 16000 / hop))
+                        win_end = min(n_frames, int((target_time + 10) * 16000 / hop))
+                        if win_start < win_end:
+                            min_idx = win_start + np.argmin(energy[win_start:win_end])
+                            cut_time = min_idx * hop / 16000.0
+                            forced_cuts.append(cut_time)
+                    if forced_cuts:
+                        forced_cuts.sort()
+                        points = [0.0] + forced_cuts + [dur]
+                        segments = []
+                        for i in range(len(points) - 1):
+                            s, e = int(points[i]*16000), int(points[i+1]*16000)
+                            seg = audio[s:e]
+                            segments.append((seg, len(seg)/16000.0))
+                        logger.info("Energy fallback split %.1fs -> %d segs %s", dur, len(segments), [f"{d:.1f}s" for _,d in segments])
+                        return segments
+                return [(audio, dur)]
+            elif not cuts:
                 return [(audio, dur)]
 
             cuts.sort()
@@ -467,7 +550,7 @@ class ASREngine:
         debug = {"duration_sec": round(duration, 1), "vad_segments": [], "context": ctx}
 
         if self._engine_type == "firered":
-            if duration <= 15.0:
+            if duration <= 120.0:
                 debug["vad_segments"] = [{"index": 0, "duration_sec": round(duration, 1)}]
                 return self._firered_backend.transcribe_audio(audio), debug
             segments = self._vad_split(audio)
diff --git a/server/backend/app/main.py b/server/backend/app/main.py
index d3b3d52..a50246e 100644
--- a/server/backend/app/main.py
+++ b/server/backend/app/main.py
@@ -220,15 +220,15 @@ def _is_hotword_hallucination(text: str, context: str, audio_peak: float = 1.0,
                               audio_dur: float = 0.0, voice_score: float = 1.0) -> bool:
     if not context or not text:
         return False
-    words = set(context.split())
+    words = set(w.lower() for w in context.split())
     cleaned = re.sub(r"[\s銆傦紝銆侊紵锛?,?!\u3000。]+", " ", text).strip()
     tokens = cleaned.split()
     if not tokens:
         return False
-    matched = sum(1 for token in tokens if token in words)
+    matched = sum(1 for token in tokens if token.lower() in words)
     consec = max_consec = 0
     for token in tokens:
-        if token in words:
+        if token.lower() in words:
             consec += 1
             max_consec = max(max_consec, consec)
         else:
@@ -239,7 +239,7 @@ def _is_hotword_hallucination(text: str, context: str, audio_peak: float = 1.0,
         return True
     # Short result composed entirely of hotwords → almost certainly hallucination.
     # Real users don't speak just a single hotword and stop.
-    if len(cleaned) <= 6 and all(t in words for t in tokens):
+    if len(cleaned) <= 6 and all(t.lower() in words for t in tokens):
         return True
     return False
 
@@ -372,11 +372,28 @@ async def _run_asr_llm(
 
     # Strip hotword context when audio has no detectable speech energy,
     # preventing the ASR model from hallucinating hotwords on noise.
-    # Whispered speech has voice_score > 0.50; noise/silence < 0.15.
+    # Three-layer detection: voice_score, energy level, and VAD.
     audio_peak = float(np.max(np.abs(audio)))
+    audio_rms = float(np.sqrt(np.mean(audio**2)))
     vs = _voice_score(audio)
-    if vs < _VS_THRESHOLD and (context is None or context):
-        logger.info("Stripping hotword context: voice_score=%.3f peak=%.4f", vs, audio_peak)
+    strip_context = False
+    if vs < _VS_THRESHOLD or (audio_peak < 0.02 and audio_rms < 0.002):
+        strip_context = True
+    elif context and duration < 10.0 and asr_engine and asr_engine._vad is not None:
+        # For short audio with hotwords: use VAD to detect if there's actual speech.
+        # This catches non-speech noise (keyboard, clicks) that has high energy.
+        import torch
+        try:
+            vad_res = asr_engine._vad.generate(
+                input=torch.tensor(audio, dtype=torch.float32), cache={}, is_final=True)
+            vad_segs = vad_res[0].get("value", []) if vad_res else []
+            logger.debug("VAD check: segs=%d, duration=%.1f", len(vad_segs), duration)
+            if not vad_segs:
+                strip_context = True
+        except Exception as e:
+            logger.warning("VAD check failed: %s", e)
+    if strip_context and (context is None or context):
+        logger.info("Stripping hotword context: voice_score=%.3f peak=%.4f rms=%.5f", vs, audio_peak, audio_rms)
         context = ""
 
     raw_text, asr_ms, asr_debug = await asr_engine.transcribe(audio, context=context, language=language)
@@ -384,6 +401,12 @@ async def _run_asr_llm(
     asr_debug["voice_score"] = round(vs, 3)
     if _is_noise(asr_text, duration, voice_score=vs) or _is_hotword_hallucination(asr_text, asr_debug.get("context", ""), audio_peak=audio_peak, audio_dur=duration, voice_score=vs):
         asr_text = ""
+    # Low energy audio producing short text is almost certainly noise/hallucination
+    if asr_text and audio_peak < 0.02 and audio_rms < 0.002 and len(asr_text) <= 10:
+        asr_text = ""
+    # VAD detected no speech but ASR produced short text → noise hallucination
+    if asr_text and strip_context and len(asr_text) <= 10:
+        asr_text = ""
 
     if cfg.logging.slow_asr_ms and asr_ms >= cfg.logging.slow_asr_ms:
         logger.warning("Slow ASR detected duration_sec=%.2f asr_ms=%d", duration, asr_ms)
diff --git a/server/config.example.yaml b/server/config.example.yaml
index fd64b71..1c5cb71 100644
--- a/server/config.example.yaml
+++ b/server/config.example.yaml
@@ -31,7 +31,7 @@ asr:
   language: "Chinese"                # Chinese / English / Cantonese
   itn: true                          # Inverse text normalization
   vllm_gpu_util: 0.5
-  vllm_max_model_len: 8192
+  vllm_max_model_len: 16384
   max_concurrency: 1
   batch_max_size: 32
   batch_wait_ms: 60