video scan: don't crash on episodes with no episode number

Plex specials/unmatched episodes can have a null index -> getattr(...,0) still
returned None -> 'NOT NULL constraint failed: episodes.episode_number'.
- Plex adapter skips episodes with no index (logged), passes a real number.
- upsert_show_tree defensively skips any episode missing season/episode number,
  so no source can crash a scan. Test added.

core/video/sources.py

@@ -122,13 +122,13 @@ class PlexVideoSource:
             "file": self._part_file(m),
         }
 
-    def _episode(self, ep, snum) -> dict:
+    def _episode(self, ep, snum, enum) -> dict:
         dur = getattr(ep, "duration", None)
         aired = getattr(ep, "originallyAvailableAt", None)
         return {
             "server_id": str(ep.ratingKey),
             "season_number": snum,
-            "episode_number": getattr(ep, "index", 0),
+            "episode_number": enum,
             "title": ep.title,
             "overview": getattr(ep, "summary", None),
             "air_date": aired.date().isoformat() if aired else None,
@@ -142,8 +142,12 @@ class PlexVideoSource:
         seasons_map = {}
         try:
             for ep in sh.episodes():
+                enum = getattr(ep, "index", None)
+                if enum is None:
+                    # No episode number (unmatched/special) — can't key it; skip.
+                    continue
                 snum = ep.parentIndex if getattr(ep, "parentIndex", None) is not None else 0
-                seasons_map.setdefault(snum, []).append(self._episode(ep, snum))
+                seasons_map.setdefault(snum, []).append(self._episode(ep, snum, enum))
         except Exception:
             logger.exception("Plex: failed reading episodes for %s", getattr(sh, "title", "?"))
         seasons = [{"server_id": None, "season_number": n, "title": None,

database/video_database.py

@@ -252,7 +252,9 @@ class VideoDatabase:
                 ).fetchone()["id"]
 
                 for ep in season.get("episodes", []):
-                    enum = ep["episode_number"]
+                    enum = ep.get("episode_number")
+                    if enum is None or snum is None:
+                        continue  # can't key an episode without season+episode numbers
                     seen_eps.add((snum, enum))
                     conn.execute(
                         "INSERT INTO episodes (show_id, season_id, server_source, server_id, "

tests/test_video_database.py

@@ -216,6 +216,17 @@ def test_upsert_show_tree_builds_seasons_episodes_and_prunes(db):
     assert eps == [1]
 
 
+def test_upsert_show_tree_skips_episodes_without_number(db):
+    sid = db.upsert_show_tree("plex", {"server_id": "s1", "title": "S", "seasons": [
+        {"season_number": 1, "episodes": [
+            {"episode_number": 1, "title": "E1"},
+            {"episode_number": None, "title": "Unmatched special"}]}]})
+    with db.connect() as c:
+        eps = [r["episode_number"] for r in c.execute(
+            "SELECT episode_number FROM episodes WHERE show_id=?", (sid,)).fetchall()]
+    assert eps == [1]
+
+
 def test_prune_missing_removes_unseen_top_level(db):
     db.upsert_movie("plex", {"server_id": "a", "title": "A"})
     db.upsert_movie("plex", {"server_id": "b", "title": "B"})