test(stats): seed lifetime media rows in legacy redistribution fixture

The reassignAnimeAnilist redistribution test seeded raw sessions and
telemetry but not the imm_lifetime_media rows a finalized session leaves
behind. The old destructive lifetime rebuild re-derived summaries from
raw sessions and hid that gap; the non-destructive recompute reads
per-video lifetime rows, so the fixture must contain them.

src/core/services/immersion-tracker-service.test.ts

@@ -3804,6 +3804,22 @@ test('reassignAnimeAnilist redistributes conflicting legacy combined row before
         (1, 2000, 1000, 1000, 1, 10, 0, 0, 0, 0, 0, 0, 0, 0),
         (2, 4000, 2000, 2000, 2, 20, 0, 0, 0, 0, 0, 0, 0, 0),
         (3, 6000, 3000, 3000, 3, 30, 0, 0, 0, 0, 0, 0, 0, 0);
+
+      -- The per-video lifetime rows those finalized sessions would have left
+      -- behind; redistributing videos re-derives imm_lifetime_anime from these.
+      INSERT INTO imm_lifetime_media (
+        video_id,
+        total_sessions,
+        total_active_ms,
+        completed,
+        first_watched_ms,
+        last_watched_ms,
+        CREATED_DATE,
+        LAST_UPDATE_DATE
+      ) VALUES
+        (1, 1, 1000, 0, '1000', '2000', 1000, 2000),
+        (2, 1, 2000, 0, '3000', '4000', 3000, 4000),
+        (3, 1, 3000, 0, '5000', '6000', 5000, 6000);
     `);
 
     await tracker.reassignAnimeAnilist(2, {