feat(player): add PWA-compatible stream casting (#33)

Add a browser-native casting service with Live and Watch player controls for Remote Playback and AirPlay-compatible devices.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

test/t33CastFeature.test.js

@@ -0,0 +1,82 @@
+const test = require('node:test');
+const assert = require('node:assert/strict');
+const fs = require('node:fs');
+const path = require('node:path');
+
+const root = path.resolve(__dirname, '..');
+const castServicePath = path.join(root, 'public', 'js', 'services', 'castService.js');
+
+function loadCastService() {
+    assert.ok(fs.existsSync(castServicePath), 'CastService module should exist at public/js/services/castService.js');
+    return require(castServicePath);
+}
+
+test('CastService reports Remote Playback availability and prompts through video.remote', async () => {
+    const CastService = loadCastService();
+    let availabilityCallback;
+    let promptCalls = 0;
+    const video = {
+        remote: {
+            watchAvailability: async callback => {
+                availabilityCallback = callback;
+                callback(true);
+                return 7;
+            },
+            prompt: async () => { promptCalls += 1; }
+        }
+    };
+
+    const service = new CastService(video);
+    await service.watchAvailability();
+    assert.equal(service.state.available, true);
+    assert.equal(service.state.type, 'remote-playback');
+    availabilityCallback(false);
+    assert.equal(service.state.available, false);
+
+    await service.prompt();
+    assert.equal(promptCalls, 1);
+});
+
+test('CastService uses AirPlay picker when webkitShowPlaybackTargetPicker is available', async () => {
+    const CastService = loadCastService();
+    let airplayCalls = 0;
+    const video = {
+        webkitShowPlaybackTargetPicker: () => { airplayCalls += 1; }
+    };
+
+    const service = new CastService(video);
+    await service.watchAvailability();
+    assert.equal(service.state.available, true);
+    assert.equal(service.state.type, 'airplay');
+
+    await service.prompt();
+    assert.equal(airplayCalls, 1);
+});
+
+test('CastService stays unsupported without native casting APIs', async () => {
+    const CastService = loadCastService();
+    const service = new CastService({});
+    await assert.doesNotReject(() => service.watchAvailability());
+    await assert.doesNotReject(() => service.prompt());
+    assert.equal(service.state.available, false);
+    assert.equal(service.state.type, 'unsupported');
+});
+
+test('Live and Watch players expose cast controls and load CastService', () => {
+    const html = fs.readFileSync(path.join(root, 'public', 'index.html'), 'utf8');
+    assert.match(html, /id="player-cast"/, 'Live player should expose a cast button');
+    assert.match(html, /id="watch-cast"/, 'Watch player should expose a cast button');
+    assert.match(html, /\/js\/services\/castService\.js/, 'index.html should load CastService before player pages');
+});
+
+test('PWA/service worker cache rules do not precache live stream endpoints', () => {
+    const publicDir = path.join(root, 'public');
+    const candidates = fs.readdirSync(publicDir)
+        .filter(name => /(?:service-worker|sw|workbox).*\.js$/i.test(name))
+        .map(name => path.join(publicDir, name));
+    for (const file of candidates) {
+        const text = fs.readFileSync(file, 'utf8');
+        assert.doesNotMatch(text, /\/api\/(?:proxy|transcode|live)/, `${path.basename(file)} should not precache stream API routes`);
+        assert.doesNotMatch(text, /\.m3u8|\.ts\b/, `${path.basename(file)} should not precache HLS playlists or segments`);
+    }
+});