Disable unavailable Identity authentication actions

Frameworks/TermindPresentation/ConnectionDecisionForms.swift

@@ -72,13 +72,14 @@ public struct SSHAuthenticationForm: View {
         !username.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty
             && (!needsPassphrase || !passphrase.isEmpty)
             && (!prompt.isProxy || !needsPasswordEntry || !password.isEmpty)
+            && !selectedIdentityPasswordIsUnavailable
     }
 
-    private var canSave: Bool {
-        guard canContinue, let selectedIdentity else { return canContinue }
-        switch library.passwordAvailability(for: selectedIdentity) {
-        case .missing, .failed: return false
-        case .notConfigured, .available: return true
+    private var selectedIdentityPasswordIsUnavailable: Bool {
+        guard let selectedIdentity else { return false }
+        return switch library.passwordAvailability(for: selectedIdentity) {
+        case .missing, .failed: true
+        case .notConfigured, .available: false
         }
     }
 
@@ -109,7 +110,7 @@ public struct SSHAuthenticationForm: View {
             if prompt.keyboardInteractive == nil, let keyboard {
                 keyboard.bridge(
                     canSubmit: canContinue,
-                    submit: { commit(save: !needsPassphrase && canSave) }, cancel: cancel)
+                    submit: { commit(save: !needsPassphrase) }, cancel: cancel)
             }
         }
         .onAppear {
@@ -249,7 +250,14 @@ public struct SSHAuthenticationForm: View {
                         Spacer()
                         continueButton
                     }
-                    saveAndContinueButton.frame(maxWidth: .infinity, alignment: .trailing)
+                    #if os(iOS)
+                        HStack {
+                            Spacer()
+                            saveAndContinueButton
+                        }
+                    #else
+                        saveAndContinueButton.frame(maxWidth: .infinity, alignment: .trailing)
+                    #endif
                 }
             }
         }
@@ -283,7 +291,7 @@ public struct SSHAuthenticationForm: View {
         }
         .buttonStyle(.borderedProminent)
         .keyboardShortcut(.defaultAction)
-        .disabled(!canSave)
+        .disabled(!canContinue)
     }
 
     private func updateFocusForRequirement() {

Memory/ARCHITECTURE.md

@@ -138,7 +138,8 @@ sibling working tree is not the app dependency. Follow `AGENTS.md` for package r
   the route. Missing local proxy passwords and explicit HTTP/SOCKS authentication rejection use the same local
   authentication surfaces across sessions, Metrics, forwarding, Assistant and external MCP requests. Proxy submissions are
   separate from SSH submissions; snapshots retain only proxy network data, username and Identity ID. An Identity whose
-  password lookup is missing or failed opens as Custom with the inherited username and cannot be overwritten while selected.
+  password lookup is missing or failed opens as Custom with the inherited username; if manually reselected, neither
+  Continue nor Save and Continue is available until the user returns to Custom or selects a usable Identity.
 - Username-only Identities try `none`, then advertised methods. Device-local `lastUsedAt` tracks successful saved-secret
   reads, not authentication. Batch route reads; missing/availability/edit reads do not count. First access per Identity/
   process writes directly without Vault journal/refresh; sync strips this field and preserves local values on apply.