fix(subtitles): only strip ASS control debris for ASS sources

- Skip control-debris stripping for primary/secondary live text when cues or source aren't ASS/SSA, so SRT lines that merely resemble ASS override tags survive
- Track active source's ASS-ness in the secondary controller and gate handleLiveText's cleanup on it

src/main/runtime/primary-subtitle-text.test.ts

@@ -218,16 +218,35 @@ test('resolvePrimarySubtitleText uses fragment grids only to account for live si
 });
 
 test('resolvePrimarySubtitleText drops malformed ASS control debris from live text', () => {
+  const cues = parseSubtitleCues(
+    [
+      '[Events]',
+      'Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text',
+      'Dialogue: 0,0:00:01.00,0:00:03.00,Default,,0,0,0,,Visible line',
+    ].join('\n'),
+    'test.ass',
+  );
+
   assert.equal(
     resolvePrimarySubtitleText({
       liveText: 'Visible line\n\\\n{\\fr0',
       currentTimeSec: 2,
-      cues: null,
+      cues,
     }),
     'Visible line',
   );
 });
 
+test('resolvePrimarySubtitleText preserves SRT text that resembles ASS control debris', () => {
+  const liveText = 'Visible line\n\\\n{\\fr0';
+  const cues = parseSubtitleCues(
+    ['1', '00:00:01,000 --> 00:00:03,000', liveText].join('\n'),
+    'test.srt',
+  );
+
+  assert.equal(resolvePrimarySubtitleText({ liveText, currentTimeSec: 2, cues }), liveText);
+});
+
 test('resolvePrimarySubtitleText keeps a fresh line starting just after the animation ended', () => {
   const text = resolvePrimarySubtitleText({
     liveText: '次のセリフ',

src/main/runtime/primary-subtitle-text.ts

@@ -14,6 +14,15 @@ export interface ResolvedPrimarySubtitle {
   cues: SubtitleCue[];
 }
 
+function cuesUseAssSyntax(cues: readonly SubtitleCue[] | null | undefined): boolean {
+  return (cues ?? []).some(
+    (cue) =>
+      cue.source === 'canonical-ass' ||
+      cue.source === 'reconstructed-ass' ||
+      cue.assLayout !== undefined,
+  );
+}
+
 function animationSpan(cue: SubtitleCue): { start: number; end: number } {
   return {
     start: cue.animationStartTime ?? cue.startTime,
@@ -235,7 +244,9 @@ export function resolvePrimarySubtitleText(options: {
   currentTimeSec: number;
   cues: readonly SubtitleCue[] | null | undefined;
 }): string {
-  const liveText = removeAssControlDebrisLines(options.liveText);
+  const liveText = cuesUseAssSyntax(options.cues)
+    ? removeAssControlDebrisLines(options.liveText)
+    : options.liveText;
   if (!liveText.trim()) {
     return liveText;
   }

src/main/runtime/secondary-subtitle-track.test.ts

@@ -406,23 +406,60 @@ test('secondary track controller falls back to live mpv text without a readable
   assert.deepEqual(broadcasts, ['live fallback']);
 });
 
-test('secondary live fallback drops malformed ASS control debris', () => {
+test('secondary ASS live fallback drops malformed control debris', async () => {
   const broadcasts: string[] = [];
   const controller = createSecondarySubtitleTrackController({
-    getMpvClient: () => null,
+    getMpvClient: () => ({
+      connected: true,
+      requestProperty: async (name) => {
+        if (name === 'secondary-sid') return 2;
+        if (name === 'track-list') return [{ type: 'sub', id: 2 }];
+        if (name === 'path') return '/media/video.mkv';
+        return null;
+      },
+    }),
     getCurrentTimePos: () => 2,
-    resolveSubtitleSource: async () => null,
+    resolveSubtitleSource: async () => ({ path: '/subs/english.ass', sourceKey: 'english' }),
     loadSubtitleSourceText: async () => '',
     parseSubtitleCues: () => [],
     setCurrentSecondaryText: () => {},
     broadcastSecondaryText: (text) => broadcasts.push(text),
   });
 
+  await controller.refresh();
+  broadcasts.length = 0;
   controller.handleLiveText('Visible line\n\\\n{\\fr0');
 
   assert.deepEqual(broadcasts, ['Visible line']);
 });
 
+test('secondary SRT live fallback preserves text that resembles ASS control debris', async () => {
+  const broadcasts: string[] = [];
+  const controller = createSecondarySubtitleTrackController({
+    getMpvClient: () => ({
+      connected: true,
+      requestProperty: async (name) => {
+        if (name === 'secondary-sid') return 2;
+        if (name === 'track-list') return [{ type: 'sub', id: 2 }];
+        if (name === 'path') return '/media/video.mkv';
+        return null;
+      },
+    }),
+    getCurrentTimePos: () => 2,
+    resolveSubtitleSource: async () => ({ path: '/subs/english.srt', sourceKey: 'english' }),
+    loadSubtitleSourceText: async () => '',
+    parseSubtitleCues: () => [],
+    setCurrentSecondaryText: () => {},
+    broadcastSecondaryText: (text) => broadcasts.push(text),
+  });
+
+  await controller.refresh();
+  broadcasts.length = 0;
+  controller.handleLiveText('Visible line\n\\\n{\\fr0');
+
+  assert.deepEqual(broadcasts, ['Visible line\n\\\n{\\fr0']);
+});
+
 test('secondary track controller reuses parsed cues for an unchanged embedded track', async () => {
   let resolveCalls = 0;
   let parseCalls = 0;

src/main/runtime/secondary-subtitle-track.ts

@@ -24,6 +24,11 @@ type SecondarySubtitleSourceInput = {
 
 const DEFAULT_REFRESH_DELAY_MS = 500;
 
+function sourceUsesAssSyntax(source: string): boolean {
+  const sourceWithoutQuery = source.split(/[?#]/u, 1)[0] ?? '';
+  return /\.(?:ass|ssa)$/iu.test(sourceWithoutQuery);
+}
+
 function finiteNumber(value: unknown, fallback = 0): number {
   const number = typeof value === 'number' ? value : Number(value);
   return Number.isFinite(number) ? number : fallback;
@@ -185,6 +190,7 @@ export function createSecondarySubtitleTrackController(deps: {
   let parsedCues: SubtitleCue[] | null = null;
   let parsedSourceKey: string | null = null;
   let parsedTrackIdentity: string | null = null;
+  let activeSourceUsesAssSyntax = false;
   let secondaryDelaySeconds = 0;
   let lastLiveText = '';
   let lastBroadcastText: string | null = null;
@@ -230,6 +236,7 @@ export function createSecondarySubtitleTrackController(deps: {
 
       const videoPath = typeof videoPathRaw === 'string' ? videoPathRaw.trim() : '';
       if (!videoPath || secondarySid === null || secondarySid === 'no') {
+        activeSourceUsesAssSyntax = false;
         useLiveFallback();
         return;
       }
@@ -251,11 +258,14 @@ export function createSecondarySubtitleTrackController(deps: {
       });
       if (generation !== refreshGeneration) return;
       if (!resolvedSource) {
+        activeSourceUsesAssSyntax = false;
         deps.logDebug?.('[secondary-subtitle-track] selected source is not readable');
         useLiveFallback();
         return;
       }
 
+      activeSourceUsesAssSyntax = sourceUsesAssSyntax(resolvedSource.path);
+
       if (resolvedSource.sourceKey === parsedSourceKey && parsedCues) {
         parsedTrackIdentity = selectedTrackIdentity;
         publish(resolveAtTime(deps.getCurrentTimePos()));
@@ -299,6 +309,7 @@ export function createSecondarySubtitleTrackController(deps: {
     parsedCues = null;
     parsedSourceKey = null;
     parsedTrackIdentity = null;
+    activeSourceUsesAssSyntax = false;
     secondaryDelaySeconds = 0;
     lastLiveText = '';
     publish('');
@@ -308,7 +319,7 @@ export function createSecondarySubtitleTrackController(deps: {
     refresh,
     scheduleRefresh,
     handleLiveText(text: string): void {
-      lastLiveText = removeAssControlDebrisLines(text);
+      lastLiveText = activeSourceUsesAssSyntax ? removeAssControlDebrisLines(text) : text;
       publish(resolveAtTime(deps.getCurrentTimePos()));
     },
     handleTimePos(timeSeconds: number): void {