fix(video): TMDB match cache never invalidated on movie<->show reclassification

The real reason a node restart alone didn't fix already-indexed entries
after the previous commit's enrichment change: _do_media_meta_request
checked media_cache's file->tmdb mapping (keyed by content hash) and
trusted it unconditionally, before ever comparing it against the file's
*current* movie/show classification. A file whose season/episode changed
on a later scan — exactly what the Specials-folder fix does, for every
file it reclassifies from "movie" to "tv" — kept answering with its
stale, wrong-kind-of-match forever, since nothing about a reclassification
touches this cache or its key.

Now falls through to a fresh search whenever the cached media_type
disagrees with what the entry resolves to right now, rather than trusting
a mapping that predates the file's current classification.

2 files changed, 51 insertions, 2 deletions

diff --git a/packages/meshbay-node/src/meshbay_node/transport/webrtc_server.py b/packages/meshbay-node/src/meshbay_node/transport/webrtc_server.py
index 724527b..2b3e3ee 100644
--- a/packages/meshbay-node/src/meshbay_node/transport/webrtc_server.py
+++ b/packages/meshbay-node/src/meshbay_node/transport/webrtc_server.py
@@ -2914,8 +2914,20 @@ class WebRTCPeerSession:
         meta = None
         tmdb_id = None
         if cached is not None:
-            tmdb_id, media_type = cached
-            meta = await media_cache.get_tmdb_meta(tmdb_id, media_type)
+            cached_tmdb_id, cached_media_type = cached
+            # Trustworthy only if it still agrees with what this file
+            # resolves to *now*. season/episode come from index-time
+            # enrichment (enrich.py), which can reclassify a file between
+            # movie and show on a later scan without this cache knowing —
+            # it is keyed by the file's content hash alone, which a
+            # reclassification never changes. Found live: an enrichment fix
+            # to a Specials-folder bug reclassified hundreds of files from
+            # "movie" to "tv", and every one kept answering with its
+            # stale movie-era match forever, because this was trusted
+            # before ever comparing media_type against the current one.
+            if cached_media_type == media_type:
+                tmdb_id = cached_tmdb_id
+                meta = await media_cache.get_tmdb_meta(tmdb_id, media_type)
 
         if meta is None:
             result, ratio = await self._tmdb_search(tmdb_client, entry, is_show)
diff --git a/packages/meshbay-node/tests/test_media_meta_request.py b/packages/meshbay-node/tests/test_media_meta_request.py
index a7355e8..a752825 100644
--- a/packages/meshbay-node/tests/test_media_meta_request.py
+++ b/packages/meshbay-node/tests/test_media_meta_request.py
@@ -112,6 +112,43 @@ async def test_two_episodes_in_the_same_season_folder_each_get_their_own_metadat
         "two different shows sharing a season folder must not resolve to the same match")
 
 
+async def test_a_reclassified_file_ignores_its_stale_cached_match(media_cache):
+    """
+    A file's classification (movie vs show) comes from its IndexEntry's
+    season/episode — set by index-time enrichment, which can change its
+    mind on a later scan (a filename-parsing fix reclassifying a whole
+    folder from "movie" to "tv", say) without media_cache's file->tmdb
+    mapping knowing anything happened: that cache is keyed by the file's
+    content hash alone, unchanged by any such reclassification. Found
+    live: exactly this scenario left every affected file answering with
+    its stale, wrong-kind-of-match forever, since the cache was trusted
+    before ever comparing media_type against what the entry resolves to
+    now.
+    """
+    index = GroupIndex(group_id="g" * 32, sk_node=Ed25519PrivateKey.generate())
+    entry = IndexEntry(id="id-1", name="ep.mkv", path="shows/Show/Specials",
+                        size=1, type="video", added_at=0,
+                        display_title="Some Show", season=0, episode=1)
+    index.add_entry(entry)
+    # Pre-populate the cache exactly as it would be left over from before
+    # entry.season/episode existed — a movie search matched to some
+    # unrelated title, cached by this file's content hash.
+    await media_cache.set_file_tmdb("id-1", "stale-movie-id", "movie")
+    await media_cache.set_tmdb_meta("stale-movie-id", "movie", {
+        "title": "An Unrelated Movie", "original_title": "An Unrelated Movie",
+        "release_date": "1999-01-01", "confidence": 1.0,
+    })
+    client = FakeTmdbClient()
+    session = _session(index, media_cache, client)
+
+    await session._do_media_meta_request({"file_id": "id-1"})
+
+    resp = session.sent[0]
+    assert resp["title"] == "Some Show"
+    assert ("tv", "Some Show") in client.searched
+    assert resp["tmdb_id"] != "stale-movie-id"
+
+
 async def test_missing_file_id_is_refused(media_cache):
     index = GroupIndex(group_id="g" * 32, sk_node=Ed25519PrivateKey.generate())
     session = _session(index, media_cache, FakeTmdbClient())