fix(calls): Push to Deafen can be switched off, and a typable deafen key can no longer fire while typing

Root cause of the 'went deaf while typing' reports: the deafen key (default
M) and Cinny's type-anywhere-to-focus-the-composer both listen on window,
so the first letter of a message typed after clicking the timeline toggled
deafen and was swallowed (reproduced: typing 'mom' → deafened, composer
shows 'om'). Now: (1) Settings → Calls → Push to Deafen has an on/off
switch (deafenHotkey); (2) a letter/digit/Space deafen key only toggles
where no composer is on screen — typing wins; (3) such keys are never
bound system-wide on desktop — only F-keys, numpad and the lock/navigation
cluster qualify (isSafeGlobalToggleKey) — so 'm' typed in another app
can't deafen you. Verified in live calls: M still toggles in the call
view, is ignored on a chat screen, switch off disables it entirely.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PPmy3tPq869XDW4njjVaKA

src/app/features/settings/general/General.tsx

@@ -112,6 +112,7 @@ import { chromeTranslationEngine } from '../../../utils/translation/chromeEngine
 import { SequenceCardStyle } from '../styles.css';
 import { useTauriUpdater } from '../../../hooks/useTauriUpdater';
 import { isTauri as isTauriEnv, invokeTauri, tauriInvoke } from '../../../hooks/useTauri';
+import { isSafeGlobalToggleKey } from '../../../hooks/useCallHotkeys';
 import { customWindowChromeAtom } from '../../../state/customWindowChrome';
 import { useDateFormatItems } from '../../../hooks/useDateFormat';
 import { useReducedMotion } from '../../../hooks/useReducedMotion';
@@ -1644,6 +1645,7 @@ function Calls() {
   const [pttMode, setPttMode] = useSetting(settingsAtom, 'pttMode');
   const [pttKey, setPttKey] = useSetting(settingsAtom, 'pttKey');
   const [deafenKey, setDeafenKey] = useSetting(settingsAtom, 'deafenKey');
+  const [deafenHotkey, setDeafenHotkey] = useSetting(settingsAtom, 'deafenHotkey');
   const [globalCallHotkeys, setGlobalCallHotkeys] = useSetting(settingsAtom, 'globalCallHotkeys');
   const [afkAutoMute, setAfkAutoMute] = useSetting(settingsAtom, 'afkAutoMute');
   const [afkTimeoutMinutes, setAfkTimeoutMinutes] = useSetting(settingsAtom, 'afkTimeoutMinutes');
@@ -1962,20 +1964,36 @@ function Calls() {
         <SettingTile
           title="Push to Deafen"
           description={
-            deafenBind.error ?? 'Toggle speaker mute during a call. Press Escape to cancel rebind.'
+            deafenBind.error ??
+            (deafenHotkey
+              ? `Press ${keyLabel(deafenKey)} during a call to mute your speakers. Press Escape to cancel rebind.${
+                  !isSafeGlobalToggleKey(deafenKey)
+                    ? ` A letter, digit or Space only works in the call view — on a chat screen typing takes priority${
+                        isTauriEnv() && globalCallHotkeys ? ' and other apps are never watched' : ''
+                      }. Bind an F-key or Numpad key to make it work everywhere.`
+                    : ''
+                }`
+              : 'Off — no key toggles deafen. Use the headphone button in the call bar.')
           }
           after={
-            <Button
-              size="300"
-              variant={deafenBind.listening ? 'Warning' : 'Secondary'}
-              fill={deafenBind.listening ? 'Solid' : 'Soft'}
-              radii="300"
-              outlined
-              onClick={deafenBind.startListening}
-              style={{ minWidth: '90px' }}
-            >
-              <Text size="B300">{deafenBind.listening ? 'Press a key…' : keyLabel(deafenKey)}</Text>
-            </Button>
+            <Box alignItems="Center" gap="200">
+              <Switch variant="Primary" value={deafenHotkey} onChange={setDeafenHotkey} />
+              {deafenHotkey && (
+                <Button
+                  size="300"
+                  variant={deafenBind.listening ? 'Warning' : 'Secondary'}
+                  fill={deafenBind.listening ? 'Solid' : 'Soft'}
+                  radii="300"
+                  outlined
+                  onClick={deafenBind.startListening}
+                  style={{ minWidth: '90px' }}
+                >
+                  <Text size="B300">
+                    {deafenBind.listening ? 'Press a key…' : keyLabel(deafenKey)}
+                  </Text>
+                </Button>
+              )}
+            </Box>
           }
         />
         {isTauriEnv() && (