fix: prime startup subtitle before autoplay resumes

- Add `selectAutoplayStartupCue` to pick active or imminent cue at startup
- Call `primeCurrentSubtitle` in warm-release before signaling autoplay ready
- Reset primed state on media path change to avoid stale cue leaks

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

@@ -19,6 +19,60 @@ test('autoplay tokenization warm release signals immediately when warmups are re
   assert.deepEqual(calls, ['signal']);
 });
 
+test('autoplay tokenization warm release primes subtitles before waiting for warmups', 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',
+    primeCurrentSubtitle: () => {
+      calls.push('prime');
+    },
+    signalAutoplayReady: () => calls.push('signal'),
+    warn: () => {},
+  });
+
+  release('/tmp/video.mkv');
+  await Promise.resolve();
+  assert.deepEqual(calls, ['prime', 'warmup']);
+
+  resolveWarmup();
+  await warmup;
+  await Promise.resolve();
+
+  assert.deepEqual(calls, ['prime', 'warmup', 'signal']);
+});
+
+test('autoplay tokenization warm release does not await subtitle priming before signaling ready media', async () => {
+  const calls: string[] = [];
+  const never = new Promise<void>(() => {});
+  const release = createAutoplayTokenizationWarmRelease({
+    isTokenizationWarmupReady: () => true,
+    startTokenizationWarmups: async () => {
+      calls.push('warmup');
+    },
+    getCurrentMediaPath: () => '/tmp/video.mkv',
+    primeCurrentSubtitle: () => {
+      calls.push('prime');
+      return never;
+    },
+    signalAutoplayReady: () => calls.push('signal'),
+    warn: () => {},
+  });
+
+  release('/tmp/video.mkv');
+  await Promise.resolve();
+
+  assert.deepEqual(calls, ['prime', 'signal']);
+});
+
 test('autoplay tokenization warm release waits for warmups before signaling current media', async () => {
   const calls: string[] = [];
   let resolveWarmup!: () => void;