fix(player): restore the subtitle sidecar work dropped by the previous commit

The previous commit was assembled from a tree read before 13264e22 landed,
so committing it reverted that commit's changes: the image-based subtitle
filtering in device_profile/types, subtitleTracks and its tests, the
regenerated bindings, and the VideoPlayer menu wiring.

Nothing was lost — the working tree held both changes throughout. This
restores those files to the merged state, leaving both the subtitle fix and
the play-session fix in place.

TRACES: UR-020, UR-004 | DR-176 | UT-168

src/lib/components/player/subtitleTracks.test.ts

@@ -53,6 +53,68 @@ describe("subtitleStreamsOf", () => {
     expect(subtitleStreamsOf(null)).toEqual([]);
     expect(subtitleStreamsOf(undefined)).toEqual([]);
   });
+
+  /**
+   * A subtitle the app cannot draw must not reach the picker. Image-based
+   * tracks (PGS/DVD/DVB) are bitmaps: the only way to show one is for the server
+   * to composite it into the video, which this app deliberately never asks for
+   * (DR-176). Offering it anyway produced the reported symptom's twin — a menu
+   * entry that selects, ticks, and shows nothing.
+   *
+   * The verdict is the backend's (`supportsExternalDelivery`); the codec
+   * vocabulary behind it stays in Rust.
+   *
+   * TRACES: UR-020 | DR-176 | UT-168
+   */
+  it("drops subtitles the backend says it cannot deliver as a sidecar", () => {
+    const streams: SubtitleStreamLike[] = [
+      { index: 2, kind: "subtitle", displayTitle: "English PGS SDH", supportsExternalDelivery: false },
+      { index: 3, kind: "subtitle", displayTitle: "English Text SDH", supportsExternalDelivery: true },
+    ];
+
+    expect(subtitleStreamsOf(streams).map((s) => s.index)).toEqual([3]);
+  });
+
+  /**
+   * Only an explicit "no" hides a track. A stream that carries no verdict at all
+   * predates the field (or came from somewhere that does not set it), and
+   * hiding those would silently empty the menu for sources that work today.
+   *
+   * TRACES: UR-020 | DR-176 | UT-168
+   */
+  it("keeps subtitles that carry no verdict", () => {
+    const streams: SubtitleStreamLike[] = [
+      { index: 2, kind: "subtitle", displayTitle: "English" },
+      { index: 3, kind: "subtitle", displayTitle: "French", supportsExternalDelivery: null },
+    ];
+
+    expect(subtitleStreamsOf(streams).map((s) => s.index)).toEqual([2, 3]);
+  });
+
+  /**
+   * The same list feeds the `<track>` children and the native play request, so
+   * an undeliverable track must not even have its URL fetched — that request is
+   * the one that 404s, and the sideloaded track it would produce is the dead
+   * entry all over again.
+   *
+   * TRACES: UR-020 | DR-176 | UT-168
+   */
+  it("never resolves a URL for a subtitle it dropped", async () => {
+    const asked: number[] = [];
+    const tracks = await resolveSubtitleTracks(
+      [
+        { index: 2, kind: "subtitle", displayTitle: "PGS", supportsExternalDelivery: false },
+        { index: 3, kind: "subtitle", displayTitle: "SRT", supportsExternalDelivery: true },
+      ],
+      async (index) => {
+        asked.push(index);
+        return url(index);
+      },
+    );
+
+    expect(asked).toEqual([3]);
+    expect(tracks.map((t) => t.streamIndex)).toEqual([3]);
+  });
 });
 
 describe("subtitleTrackLabel", () => {