Fix crash on vinyl track positions like 'A1', 'B2' from MusicBrainz

MusicBrainz returns vinyl track numbers as 'A1', 'B3' etc. instead of
plain integers. int('A1') raised ValueError crashing the entire album.

metadata_resolver.py: parse vinyl positions with regex before int():
- 'A1' → track 1, disc 1 (side A)
- 'B3' → track 3, disc 1 (side B)
- 'C1' → track 1, disc 2 (side C)
- Non-vinyl: extract first digit group via re.search

hint_extractor.py: guard int(tl_track) in tracklist matching with
try/except + re.search so any non-numeric track position is skipped
gracefully instead of crashing.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

metadata_resolver.py

@@ -549,9 +549,20 @@ def resolve(
             for medium in full_release.get("medium-list", []):
                 disc_num = medium.get("position", 1)
                 for track in medium.get("track-list", []):
+                    raw_num = str(track.get("number", "0") or "0").strip()
+                    # Vinyl: "A1"→track 1 disc 1, "B3"→track 3 disc 1, "C1"→disc 2, "D1"→disc 2
+                    vinyl_match = re.match(r"^([A-Za-z])(\d+)$", raw_num)
+                    if vinyl_match:
+                        side_letter = vinyl_match.group(1).upper()
+                        track_number = int(vinyl_match.group(2))
+                        # A,B → disc 1; C,D → disc 2; E,F → disc 3 …
+                        disc_num = (ord(side_letter) - ord("A")) // 2 + 1
+                    else:
+                        num_match = re.search(r"\d+", raw_num)
+                        track_number = int(num_match.group()) if num_match else 0
                     mb_tracks.append({
                         "disc": disc_num,
-                        "number": int(track.get("number", 0) or 0),
+                        "number": track_number,
                         "title": track.get("recording", {}).get("title", ""),
                         "artist": track.get("artist-credit-phrase", ""),
                         "mbid": track.get("recording", {}).get("id"),