feat(arr): reconcile subtitle gaps in the daemon

Closes each unsatisfied wanted language per DESIGN.md §8/§15: embedded
tracks satisfy for free (recording them as #189 left to this issue),
then provider search + ranked fetch + alass sync + sidecar write, then
immediate machine translation — extracting a text-format embedded track
when that is the only source — and otherwise the reason lands on the
attempt row for the missing-subtitles queue.

Closes run as detached tasks because alass and translation outlive the
25 s reconcile action budget; every outcome is recorded in domain rows
first, so a crash converges on the next tick. Failures back off on the
same §6.2 curve as movie searches; a rate-limited provider is the
'capped' queue state; unreachable providers and translators fold into
the existing §9.5 broken notification, edge-triggered.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.sqlx/query-35ace0417f613340f82522549d70d0dffeb680afb57511cb17fa15b3a571b974.json

@@ -0,0 +1,12 @@
+{
+  "db_name": "SQLite",
+  "query": "INSERT INTO subtitle_attempts (media_file_id, language)\n         SELECT id, ? FROM media_files WHERE probed IS NOT NULL\n         ON CONFLICT (media_file_id, language) DO NOTHING",
+  "describe": {
+    "columns": [],
+    "parameters": {
+      "Right": 1
+    },
+    "nullable": []
+  },
+  "hash": "35ace0417f613340f82522549d70d0dffeb680afb57511cb17fa15b3a571b974"
+}