fix(calls): release a push-to-talk hold after 5 minutes (#136)

Elbow-on-the-keyboard guard: a PTT hold longer than 5 min (fixed, not a
setting) is released exactly like a keyup — pttActive off, mic muted — with a
toast 'Push to talk released after 5 minutes — press the key again to keep
talking.' A fresh press re-engages normally. One watchdog shared by the DOM
path and the desktop-global hotkey path; keydown auto-repeat no longer
restarts anything; non-PTT mode, deafen and the mic button are untouched.
Helper unit-tested with fake timers; verified headless with Playwright's clock:
held → still open at +4 min → released + toast at +5 min → re-press works.

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

src/app/utils/pttHoldWatchdog.test.ts

@@ -0,0 +1,74 @@
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import { createPttHoldWatchdog } from './pttHoldWatchdog';
+
+const fake = () => {
+  let now = 0;
+  const timers = new Map<number, { at: number; fn: () => void }>();
+  let seq = 0;
+  return {
+    timers: {
+      setTimeout: (fn: () => void, ms: number) => {
+        seq += 1;
+        timers.set(seq, { at: now + ms, fn });
+        return seq;
+      },
+      clearTimeout: (h: unknown) => {
+        timers.delete(h as number);
+      },
+    },
+    advance(ms: number) {
+      now += ms;
+      [...timers.entries()]
+        .filter(([, t]) => t.at <= now)
+        .forEach(([id, t]) => {
+          timers.delete(id);
+          t.fn();
+        });
+    },
+  };
+};
+
+test('a hold past the limit expires once; a release before it never does', () => {
+  const clock = fake();
+  let expired = 0;
+  const w = createPttHoldWatchdog(
+    () => {
+      expired += 1;
+    },
+    1000,
+    clock.timers,
+  );
+  w.arm();
+  clock.advance(999);
+  assert.equal(expired, 0);
+  clock.advance(1);
+  assert.equal(expired, 1);
+  assert.equal(w.armed(), false);
+
+  w.arm();
+  clock.advance(500);
+  w.disarm();
+  clock.advance(2000);
+  assert.equal(expired, 1);
+});
+
+test('re-pressing restarts the clock', () => {
+  const clock = fake();
+  let expired = 0;
+  const w = createPttHoldWatchdog(
+    () => {
+      expired += 1;
+    },
+    1000,
+    clock.timers,
+  );
+  w.arm();
+  clock.advance(800);
+  w.disarm();
+  w.arm();
+  clock.advance(800);
+  assert.equal(expired, 0);
+  clock.advance(200);
+  assert.equal(expired, 1);
+});

src/app/utils/pttHoldWatchdog.ts

@@ -0,0 +1,40 @@
+/**
+ * [Gitea #136] Elbow-on-the-keyboard guard for push-to-talk: a hold longer
+ * than `maxMs` is released as if the key came up. `arm()` on press, `disarm()`
+ * on release (a genuine release + re-press restarts the clock). Timers are
+ * injectable for tests.
+ */
+export const PTT_MAX_HOLD_MS = 5 * 60 * 1000;
+
+type Timers = {
+  setTimeout: (fn: () => void, ms: number) => unknown;
+  clearTimeout: (handle: unknown) => void;
+};
+
+const realTimers: Timers = {
+  setTimeout: (fn, ms) => setTimeout(fn, ms),
+  clearTimeout: (h) => clearTimeout(h as ReturnType<typeof setTimeout>),
+};
+
+export const createPttHoldWatchdog = (
+  onExpire: () => void,
+  maxMs = PTT_MAX_HOLD_MS,
+  timers: Timers = realTimers,
+) => {
+  let handle: unknown;
+  const disarm = () => {
+    if (handle !== undefined) timers.clearTimeout(handle);
+    handle = undefined;
+  };
+  return {
+    arm: () => {
+      disarm();
+      handle = timers.setTimeout(() => {
+        handle = undefined;
+        onExpire();
+      }, maxMs);
+    },
+    disarm,
+    armed: () => handle !== undefined,
+  };
+};