feat(voice): reconcile preview and settings with main

add the shared Voice Preview and Settings panel with browser-local preview
and inactivity preferences, keyboard controls and responsive positioning

preserve main’s Rotation and Context behavior, clarify panel routing and
refresh schema pins within the unchanged prompt limit

src/voice/panel/inactivity.test.mjs

@@ -0,0 +1,108 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import { createVoiceInactivity } from './inactivity.js';
+function fixture() {
+  let activity = {
+    known: true,
+    connected: true,
+    held: false,
+    inputBusy: false,
+    outputBusy: false,
+    generationBusy: false,
+  };
+  let pending = 0,
+    expired = 0,
+    time = 100,
+    serial = 0;
+  const timers = new Map();
+  const idle = createVoiceInactivity({
+    readActivity: () => activity,
+    readPending: () => pending,
+    onExpire: () => expired++,
+    now: () => time,
+    setTimer: (fn, delay) => {
+      timers.set(++serial, { fn, delay });
+      return serial;
+    },
+    clearTimer: (id) => timers.delete(id),
+  });
+  return {
+    idle,
+    activity,
+    timers,
+    setPending: (n) => (pending = n),
+    expired: () => expired,
+    fire: () => {
+      const entry = [...timers][0];
+      timers.delete(entry[0]);
+      entry[1].fn();
+    },
+    tick: (n) => (time += n),
+  };
+}
+test('one clock; quiet arms default five minutes; busy blocks and quiescence rearms', () => {
+  const f = fixture();
+  assert.equal([...f.timers.values()][0].delay, 300000);
+  assert.equal(f.idle.snapshot().deadline, 300100);
+  f.activity.outputBusy = true;
+  f.idle.update();
+  assert.equal(f.timers.size, 0);
+  f.activity.outputBusy = false;
+  f.tick(200);
+  f.idle.update();
+  assert.equal(f.idle.snapshot().deadline, 300300);
+  f.fire();
+  assert.equal(f.expired(), 1);
+});
+test('actual activity resets but silent unchanged snapshots do not', () => {
+  const f = fixture();
+  const deadline = f.idle.snapshot().deadline;
+  f.tick(1000);
+  f.idle.update();
+  assert.equal(f.idle.snapshot().deadline, deadline);
+  f.idle.update({ activity: true });
+  assert.equal(f.idle.snapshot().deadline, deadline + 1000);
+});
+test('None cancels; invalid values cannot replace setting; explicit retry rearms', () => {
+  const f = fixture();
+  assert.equal(f.idle.setMinutes(0), true);
+  assert.equal(f.timers.size, 0);
+  for (const bad of [1.5, -1, 61, '5', NaN])
+    assert.equal(f.idle.setMinutes(bad), false);
+  assert.equal(f.idle.setMinutes(1), true);
+  assert.equal([...f.timers.values()][0].delay, 60000);
+});
+test('expiry rereads held, unknown and pending counts despite missing update', () => {
+  for (const kind of ['held', 'unknown', 'pending']) {
+    const f = fixture();
+    if (kind === 'held') f.activity.held = true;
+    if (kind === 'unknown') f.activity.known = false;
+    if (kind === 'pending') f.setPending(2);
+    f.fire();
+    assert.equal(f.expired(), 0);
+  }
+});
+test('pending siblings and held-before-connect forbid timer; stale callback cannot expire', () => {
+  const f = fixture();
+  const stale = [...f.timers.values()][0].fn;
+  f.setPending(2);
+  f.idle.update();
+  stale();
+  assert.equal(f.expired(), 0);
+  f.setPending(1);
+  f.idle.update();
+  assert.equal(f.timers.size, 0);
+  f.setPending(0);
+  f.activity.connected = false;
+  f.activity.held = true;
+  f.idle.update();
+  assert.equal(f.timers.size, 0);
+  f.activity.connected = true;
+  f.idle.update();
+  assert.equal(f.timers.size, 0);
+  f.activity.held = false;
+  f.idle.update();
+  assert.equal(f.timers.size, 1);
+  f.idle.destroy();
+  assert.equal(f.timers.size, 0);
+});