feat(node,hub): add Videos group app (poster grid, flat list, TMDB metadata)

Implements docs/mediacenter.md: a "Videos" group application built on the
existing files index rather than a separate catalogue. On the node side,
new indexer enrichment (technical probe, filename/season parsing, thumbnail
generation) runs per-file once an operator has chosen a video_root for the
group, plus a TMDB client for on-demand poster/metadata lookups (never
client-side, thumbnails delivered over the existing chunk path). On the hub
side, a new video-app.js renders a lazily-mounted poster grid or a
thumbnail-only flat list, with TMDB entirely optional per group.

Along the way: the global apps registry now drives Settings' default-tab
picker instead of a hardcoded list, and the video_root is configured from
group Settings (like uploads) rather than from Files, with the node
refusing to run any TMDB/thumbnail work until one is set.

Fixes several bugs found via live testing against a real library, notably
a race between two effects writing the same "image ready" state that could
leave a poster grid spinning forever on a same-tab revisit — see
mediacenter.md §5.4 for the full account of each one.

1 files changed, 71 insertions, 0 deletions

diff --git a/packages/meshbay-node/tests/test_media_cache.py b/packages/meshbay-node/tests/test_media_cache.py
new file mode 100644
index 0000000..b66c448
--- /dev/null
+++ b/packages/meshbay-node/tests/test_media_cache.py
@@ -0,0 +1,71 @@
+"""Tests for media_cache.py — TMDB/thumbnail cache and its pruning obligation."""
+
+import time
+
+import pytest
+
+from meshbay_node.media_cache import MediaCache, TMDB_META_TTL_SECS
+
+
+@pytest.fixture
+async def cache(tmp_path):
+    c = MediaCache(db_path=tmp_path / "media_cache.db")
+    await c.open()
+    yield c
+    await c.close()
+
+
+@pytest.mark.asyncio
+async def test_file_tmdb_round_trip(cache):
+    assert await cache.get_file_tmdb("file1") is None
+
+    await cache.set_file_tmdb("file1", "12345", "movie")
+
+    assert await cache.get_file_tmdb("file1") == ("12345", "movie")
+
+
+@pytest.mark.asyncio
+async def test_tmdb_meta_round_trip(cache):
+    assert await cache.get_tmdb_meta("12345", "movie") is None
+
+    await cache.set_tmdb_meta("12345", "movie", {"title": "A Movie", "vote_average": 7.5})
+
+    meta = await cache.get_tmdb_meta("12345", "movie")
+    assert meta == {"title": "A Movie", "vote_average": 7.5}
+
+
+@pytest.mark.asyncio
+async def test_tmdb_meta_expires_after_ttl(cache):
+    await cache._db.execute(
+        "INSERT INTO tmdb_meta (tmdb_id, media_type, json, fetched_at) VALUES (?, ?, ?, ?)",
+        ("999", "movie", '{"title": "Old"}', time.time() - TMDB_META_TTL_SECS - 1),
+    )
+    await cache._db.commit()
+
+    assert await cache.get_tmdb_meta("999", "movie") is None
+
+
+@pytest.mark.asyncio
+async def test_thumb_round_trip(cache):
+    assert await cache.get_thumb("thumbhash1") is None
+
+    await cache.put_thumb("thumbhash1", "file1", b"\xff\xd8fakejpeg")
+
+    assert await cache.get_thumb("thumbhash1") == b"\xff\xd8fakejpeg"
+
+
+@pytest.mark.asyncio
+async def test_prune_file_removes_thumb_and_mapping_but_not_shared_meta(cache):
+    # Two episodes of the same show share one tmdb_meta row (§2's stated case).
+    await cache.set_file_tmdb("ep1", "555", "tv")
+    await cache.set_file_tmdb("ep2", "555", "tv")
+    await cache.set_tmdb_meta("555", "tv", {"name": "A Show"})
+    await cache.put_thumb("thumb-ep1", "ep1", b"jpeg-bytes-1")
+
+    await cache.prune_file("ep1")
+
+    assert await cache.get_file_tmdb("ep1") is None
+    assert await cache.get_thumb("thumb-ep1") is None
+    # ep2's own mapping and the shared show metadata both survive
+    assert await cache.get_file_tmdb("ep2") == ("555", "tv")
+    assert await cache.get_tmdb_meta("555", "tv") == {"name": "A Show"}