fix(subtitles): follow mpv sub-delay in mining, sidebar, and navigation (#302)

src/core/services/mpv-protocol.test.ts

@@ -73,6 +73,8 @@ function createDeps(overrides: Partial<MpvProtocolHandleMessageDeps> = {}): {
       getCurrentSubStart: () => 0,
       setCurrentSubEnd: () => {},
       getCurrentSubEnd: () => 0,
+      setCurrentSubDelay: () => {},
+      getCurrentSubDelay: () => 0,
       emitMediaPathChange: (payload) => {
         state.mediaPath = payload.path;
       },
@@ -131,6 +133,22 @@ test('dispatchMpvProtocolMessage emits subtitle text on property change', async
   assert.deepEqual(state.events, [{ text: '字幕', isOverlayVisible: false }]);
 });
 
+test('dispatchMpvProtocolMessage tracks sub-delay retiming', async () => {
+  const delays: number[] = [];
+  const { deps } = createDeps({ setCurrentSubDelay: (value) => delays.push(value) });
+
+  await dispatchMpvProtocolMessage(
+    { event: 'property-change', name: 'sub-delay', data: 1.5 },
+    deps,
+  );
+  await dispatchMpvProtocolMessage(
+    { event: 'property-change', name: 'sub-delay', data: null },
+    deps,
+  );
+
+  assert.deepEqual(delays, [1.5, 0]);
+});
+
 test('dispatchMpvProtocolMessage widens halfwidth katakana in subtitle text', async () => {
   const { deps, state } = createDeps();
 
@@ -379,6 +397,29 @@ test('dispatchMpvProtocolMessage pauses on sub-end when pendingPauseAtSubEnd is
   });
 });
 
+test('dispatchMpvProtocolMessage pauses at the sub-delay retimed sub-end', async () => {
+  let pauseAtTime: number | null = null;
+  let subDelay = 1.5;
+  const { deps } = createDeps({
+    getPendingPauseAtSubEnd: () => true,
+    getCurrentSubDelay: () => subDelay,
+    setCurrentSubDelay: (next) => {
+      subDelay = next;
+    },
+    getPauseAtTime: () => pauseAtTime,
+    setPauseAtTime: (next) => {
+      pauseAtTime = next;
+    },
+  });
+
+  await dispatchMpvProtocolMessage({ event: 'property-change', name: 'sub-end', data: 42 }, deps);
+  assert.equal(pauseAtTime, 43.5);
+
+  // Retiming before the replay reaches its end moves the pause with the line.
+  await dispatchMpvProtocolMessage({ event: 'property-change', name: 'sub-delay', data: 2 }, deps);
+  assert.equal(pauseAtTime, 44);
+});
+
 test('dispatchMpvProtocolMessage updates current time before emitting time-pos change', async () => {
   const calls: string[] = [];
   let currentTimePos = 0;