fix(player): carry a picked subtitle language across episodes with sparse tags

The cross-item subtitle intent required declared languages on both sides,
and a null on either side counted as a contradiction. Any untagged track -
common when a title like "Swedish" is the only signal - declined on every
episode advance, fell to the server's per-item priority, and turned the
viewer's subtitles off (a 2.11.0 regression from the #1716/#1717 hard
gates).

A unique real title match now vouches for a row when language evidence is
missing on either side. Declared languages that disagree still decline no
matter what the title says, forced-class parity is untouched, codec and
external parity only break ties within the title-matched set, and a
residual tie declines rather than guesses, so the wrong-track class of
#1716 stays closed.

A decline is also no longer laundered into a viewer decision: the resolver
keeps the unserved preference on the selection, the open flow hands it to
the track manager instead of a navigation-priority off (late native tracks
may carry the container tags the server rows lack), the next episode
boundary re-carries it instead of hardening it into an explicit off, and
progress reports withhold the -1 subtitle index that would otherwise come
back as the item's server-side default forever.

A pick the screen could not map to a source row (no subtitle catalog, or
an identity-matcher miss) previously never reached the committed session
selection at all, so the next episode carried the stale off while the
picked track was visibly on screen. Such picks now commit the raw native
track without source ids and demote to a semantic intent at the boundary.

close #1785

test/screens/video_player/player_initialization_lifecycle_test.dart

@@ -6,6 +6,8 @@ import 'package:flutter_test/flutter_test.dart';
 import 'package:plezy/focus/focusable_button.dart';
 import 'package:plezy/providers/playback_state_provider.dart';
 import 'package:plezy/mpv/mpv.dart';
+import 'package:plezy/media/media_source_info.dart';
+import 'package:plezy/services/playback_subtitle_resolver.dart';
 import 'package:plezy/screens/video_player_screen.dart';
 import 'package:plezy/services/settings_service.dart';
 import 'package:plezy/services/subtitle_preference.dart';
@@ -117,6 +119,146 @@ void main() {
     expect((result! as SubtitleIntentPreference).intent.language, 'eng');
   });
 
+  test('a declined committed off re-carries the declined preference (#1785)', () {
+    const declined = SubtitlePreference.intent(
+      SubtitleIntent(language: 'swe', forced: false, title: 'Swedish', codec: 'srt'),
+    );
+
+    // The committed off is fallout from a declined carry: with the player
+    // also off, the declined preference itself keeps crossing boundaries.
+    expect(
+      subtitlePreferenceForItemChange(
+        hasCommittedSelection: true,
+        committedTrack: SubtitleTrack.off,
+        nativeTrack: SubtitleTrack.off,
+        declinedPreference: declined,
+      ),
+      declined,
+    );
+  });
+
+  test('live native state outranks a declined carry after a late rescue (#1785)', () {
+    const declined = SubtitlePreference.intent(
+      SubtitleIntent(language: 'swe', forced: false, title: 'Swedish', codec: 'srt'),
+    );
+
+    final result = subtitlePreferenceForItemChange(
+      hasCommittedSelection: true,
+      committedTrack: SubtitleTrack.off,
+      nativeTrack: const SubtitleTrack(id: '5', language: 'swe', title: 'Swedish', codec: 'srt'),
+      declinedPreference: declined,
+    );
+
+    expect(result, isA<SubtitleIntentPreference>());
+    expect((result! as SubtitleIntentPreference).intent.language, 'swe');
+  });
+
+  test('a declined stale source reference crosses the boundary as its intent (#1785)', () {
+    const declined = SubtitlePreference.track(
+      SubtitleTrack(id: 'source:9', title: 'Swedish', language: 'swe', codec: 'srt'),
+    );
+
+    final result = subtitlePreferenceForItemChange(
+      hasCommittedSelection: true,
+      committedTrack: SubtitleTrack.off,
+      nativeTrack: SubtitleTrack.off,
+      declinedPreference: declined,
+    );
+
+    expect(result, isA<SubtitleIntentPreference>());
+    expect((result! as SubtitleIntentPreference).intent.language, 'swe');
+  });
+
+  test('a pick without source identity is committed raw and carries as an intent (#1785)', () {
+    // The identity matcher failed (or the item has no subtitle rows): the
+    // committed selection must still reflect the pick on screen, not the
+    // session's previous choice.
+    const picked = SubtitleTrack(id: '3', title: 'Swedish', language: 'swe', codec: 'srt');
+
+    final selection = subtitleSelectionForUserPick(
+      currentSelection: const PlaybackSubtitleSelection.off(),
+      isPrimarySlot: true,
+      track: picked,
+    );
+
+    expect(selection.primaryTrack, picked);
+    expect(selection.primarySourceStreamId, isNull);
+    expect(selection.primarySidecar, isNull);
+
+    // Next episode boundary: the raw commit demotes to a semantic intent
+    // instead of hardening the stale off.
+    final carried = subtitlePreferenceForItemChange(
+      hasCommittedSelection: true,
+      committedTrack: selection.primaryTrack,
+      nativeTrack: picked,
+    );
+    expect(carried, isA<SubtitleIntentPreference>());
+    expect((carried! as SubtitleIntentPreference).intent.language, 'swe');
+  });
+
+  test('a source-backed pick keeps its source identity in the committed selection', () {
+    final sourceTrack = MediaSubtitleTrack(
+      id: 7,
+      languageCode: 'swe',
+      title: 'Swedish',
+      codec: 'srt',
+      selected: false,
+      forced: false,
+    );
+
+    final selection = subtitleSelectionForUserPick(
+      currentSelection: const PlaybackSubtitleSelection.off(),
+      isPrimarySlot: true,
+      track: const SubtitleTrack(id: '3', title: 'Swedish', language: 'swe', codec: 'srt'),
+      sourceTrack: sourceTrack,
+    );
+
+    expect(selection.primaryTrack.id, 'source:7');
+    expect(selection.primarySourceStreamId, 7);
+  });
+
+  test('a secondary-slot pick leaves the committed primary untouched', () {
+    const primary = SubtitleTrack(id: 'source:4', title: 'Swedish', language: 'swe', codec: 'srt');
+    const secondaryPick = SubtitleTrack(id: '5', title: 'English', language: 'eng', codec: 'srt');
+
+    final selection = subtitleSelectionForUserPick(
+      currentSelection: const PlaybackSubtitleSelection(primaryTrack: primary, primarySourceStreamId: 4),
+      isPrimarySlot: false,
+      track: secondaryPick,
+    );
+
+    expect(selection.primaryTrack, primary);
+    expect(selection.primarySourceStreamId, 4);
+    expect(selection.secondaryTrack, secondaryPick);
+    expect(selection.secondarySourceStreamId, isNull);
+  });
+
+  test('a secondary-only change keeps the primary declined carry alive (#1785)', () {
+    const declined = SubtitlePreference.intent(
+      SubtitleIntent(language: 'swe', forced: false, title: 'Swedish', codec: 'srt'),
+    );
+    const current = PlaybackSubtitleSelection.off(declinedPreference: declined);
+
+    final selection = subtitleSelectionForUserPick(
+      currentSelection: current,
+      isPrimarySlot: false,
+      track: const SubtitleTrack(id: '5', title: 'English', language: 'eng', codec: 'srt'),
+    );
+
+    // The primary off stays fallout, not a decision: -1 must remain withheld
+    // and the next boundary must still re-carry the intent.
+    expect(selection.primaryTrack.id, SubtitleTrack.off.id);
+    expect(selection.declinedPreference, declined);
+
+    // A primary decision retires the carry.
+    final decided = subtitleSelectionForUserPick(
+      currentSelection: selection,
+      isPrimarySlot: true,
+      track: const SubtitleTrack(id: '3', title: 'Swedish', language: 'swe', codec: 'srt'),
+    );
+    expect(decided.declinedPreference, isNull);
+  });
+
   testWidgets('initialization ownership serializes rollback, retry, and route removal', (tester) async {
     final failedDispose = Completer<void>();
     final replacementInitialize = Completer<bool>();