feat(i18n): the server's closed English vocabularies named in the reader's language (E30 S2)

- lib/vocab + the `vocab` locale area: TMDB crew jobs and departments, auto-tags (D1 A: the data
  stays English, the catalog is named at its one source, useTags), built-in download profiles,
  YouTube topics; held key-for-key to the backend's own lists by backendIds.contract.
- Countries by ISO code: TMDB parse stores {code, name}; rows stored before are coded from TMDB's
  own country list in one request (run_enrich); Intl names them, historic codes (YU, SU, XI…)
  from the catalog.
- Player tracks named from the language tag, forced/SDH flags and codec tail, not Plex's
  server-language displayTitle; no invented "Audio N" on the server.
- Download lifecycle notices (shared / expiring / expired / evicted) named from data; the share
  notice carries the title.
- Scheduler: the job result rides along as data and is named per key (dashboard + run notice).
- Invite status named; a render crash's notice no longer shows the engine's English message.
- Fix: YouTube links …/wiki/Humour, the tagger looked for "Humor" — Comedy never came from a topic.

backend/tests/test_download_share_notice.py

@@ -0,0 +1,41 @@
+"""E30: the "shared with you" notice carries the download's title in its data, so the client can name
+the notice in the reader's language. Its stored title is an English sentence ("Cats was shared with
+you") — the only place the title lived, so a Hungarian reader got the English. Needs the DB."""
+
+from sqlalchemy import select
+
+from app.models import DownloadJob, MediaAsset, Notification
+
+
+def test_a_share_notice_carries_the_title_and_the_sharer(db, make_user, as_user):
+    owner = make_user("owner@example.com")
+    friend = make_user("friend@example.com")
+    asset = MediaAsset(
+        source_kind="url", source_ref="share-e30", format_sig="sig", status="ready", ref_count=1
+    )
+    db.add(asset)
+    db.flush()
+    job = DownloadJob(
+        user_id=owner.id,
+        asset_id=asset.id,
+        source_kind="url",
+        source_ref="share-e30",
+        status="done",
+        queue_pos=1,
+        profile_snapshot={},
+        display_name="Cats",
+    )
+    db.add(job)
+    db.commit()
+
+    r = as_user(owner).post(f"/api/downloads/{job.id}/share", json={"email": "friend@example.com"})
+    assert r.status_code == 200, r.text
+
+    notice = db.execute(select(Notification).where(Notification.user_id == friend.id)).scalar_one()
+    assert notice.type == "download_shared"
+    assert notice.data == {
+        "kind": "download_shared",
+        "from": "owner@example.com",
+        "job_id": job.id,
+        "title": "Cats",
+    }