fix: managed playback overlay lifecycle for launcher-owned sessions

- Remove --background from launcher-owned mpv starts; quit only non-tray/non-background managed sessions
- Defer autoplay-ready signal until overlay window content is loaded; retry after flush
- Retry socket availability before auto-starting overlay (up to 25 attempts, 200ms apart)
- Extract warm tokenization signal into autoplay-tokenization-warm-release with stale-media guard
- Queue second-instance commands until app ready runtime completes
- Guard globalShortcut cleanup with isAppReady check to avoid pre-ready crash
- Recognize "osx" as a macOS platform alias in Lua environment detection

src/main/runtime/autoplay-tokenization-warm-release.test.ts

@@ -0,0 +1,69 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import { createAutoplayTokenizationWarmRelease } from './autoplay-tokenization-warm-release';
+
+test('autoplay tokenization warm release signals immediately when warmups are ready', () => {
+  const calls: string[] = [];
+  const release = createAutoplayTokenizationWarmRelease({
+    isTokenizationWarmupReady: () => true,
+    startTokenizationWarmups: async () => {
+      calls.push('warmup');
+    },
+    getCurrentMediaPath: () => '/tmp/video.mkv',
+    signalAutoplayReady: () => calls.push('signal'),
+    warn: () => {},
+  });
+
+  release('/tmp/video.mkv');
+
+  assert.deepEqual(calls, ['signal']);
+});
+
+test('autoplay tokenization warm release waits for warmups before signaling current media', async () => {
+  const calls: string[] = [];
+  let resolveWarmup!: () => void;
+  const warmup = new Promise<void>((resolve) => {
+    resolveWarmup = resolve;
+  });
+  const release = createAutoplayTokenizationWarmRelease({
+    isTokenizationWarmupReady: () => false,
+    startTokenizationWarmups: async () => {
+      calls.push('warmup');
+      await warmup;
+    },
+    getCurrentMediaPath: () => '/tmp/video.mkv',
+    signalAutoplayReady: () => calls.push('signal'),
+    warn: () => {},
+  });
+
+  release('/tmp/video.mkv');
+  await Promise.resolve();
+  assert.deepEqual(calls, ['warmup']);
+
+  resolveWarmup();
+  await warmup;
+  await Promise.resolve();
+
+  assert.deepEqual(calls, ['warmup', 'signal']);
+});
+
+test('autoplay tokenization warm release skips stale media after warmup resolves', async () => {
+  const calls: string[] = [];
+  let currentMediaPath = '/tmp/video-2.mkv';
+  const release = createAutoplayTokenizationWarmRelease({
+    isTokenizationWarmupReady: () => false,
+    startTokenizationWarmups: async () => {
+      calls.push('warmup');
+    },
+    getCurrentMediaPath: () => currentMediaPath,
+    signalAutoplayReady: () => calls.push('signal'),
+    warn: () => {},
+  });
+
+  release('/tmp/video-1.mkv');
+  await Promise.resolve();
+  currentMediaPath = '/tmp/video-3.mkv';
+  await Promise.resolve();
+
+  assert.deepEqual(calls, ['warmup']);
+});