fix: address code review findings

- notifier: show artist display names (not internal IDs) in digest; resolve
  names from artist_settings and fall back to ID when unavailable
- notifier: skip sending an empty digest to avoid daily spam
- config: require telegram token/chat_id when enabled
- web: warn loudly when auth is disabled on a non-loopback bind; add HTTP
  server timeouts
- web: treat SetReleaseIgnored "release not found" as benign redirect (0 rows)
- musicbrainz: reject low-score/name-mismatched MBID resolutions instead of
  silently caching the wrong artist
- database: remove dead duplicate err check; harden DSN param appending
- musicbrainz: check rows.Err() after iterating existing releases

internal/musicbrainz/resolve.go

@@ -4,7 +4,10 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"log"
 	"net/url"
+
+	"naviwatcher/internal/normalize"
 )
 
 // mbArtistSearchResult models the JSON response of the MusicBrainz artist
@@ -18,11 +21,20 @@ type mbArtistSearchResult struct {
 	} `json:"artists"`
 }
 
+// minResolutionScore is the minimum MusicBrainz search score (0-100) we accept
+// for an MBID resolution. Below this, the best hit is too weak a match to
+// trust, and caching it would silently pollute an artist's discography with
+// the wrong MusicBrainz data.
+const minResolutionScore = 80
+
 // ResolveArtistMBID resolves a MusicBrainz artist ID (MBID) for the given
 // artist name by querying the MusicBrainz artist search endpoint. It returns
-// the ID of the first (best-scoring) matching artist. An error is returned if
-// the search yields no matches, the response cannot be parsed, or the
-// underlying request fails.
+// the ID of the highest-scoring matching artist, but only when that artist's
+// normalized name actually matches the requested name (and its search score is
+// at or above minResolutionScore). An error is returned if the search yields
+// no usable match, the response cannot be parsed, or the underlying request
+// fails. Rejecting a low-confidence hit lets the caller surface the problem
+// instead of caching a wrong MBID.
 func (c *MusicBrainzClient) ResolveArtistMBID(ctx context.Context, name string) (string, error) {
 	params := url.Values{}
 	params.Set("query", fmt.Sprintf("artist:%s", name))
@@ -43,5 +55,16 @@ func (c *MusicBrainzClient) ResolveArtistMBID(ctx context.Context, name string)
 		return "", fmt.Errorf("no MusicBrainz artist found for %q", name)
 	}
 
-	return result.Artists[0].ID, nil
+	best := result.Artists[0]
+	if best.Score < minResolutionScore {
+		return "", fmt.Errorf("no confident MusicBrainz match for %q (best candidate %q scored %d, need >= %d)", name, best.Name, best.Score, minResolutionScore)
+	}
+	// Even with a high score, require the normalized name to match, guarding
+	// against score inflation on name collisions (e.g. tribute acts).
+	if normalize.NormalizeArtistName(best.Name) != normalize.NormalizeArtistName(name) {
+		log.Printf("MusicBrainz MBID resolution skipped for %q: best candidate %q did not match by name", name, best.Name)
+		return "", fmt.Errorf("best MusicBrainz candidate %q does not match %q by name", best.Name, name)
+	}
+
+	return best.ID, nil
 }

internal/musicbrainz/sync.go

@@ -114,6 +114,10 @@ func SyncArtistDiscography(
 		}
 		ignoredMap[rgid] = ignored
 	}
+	if err := rows.Err(); err != nil {
+		rows.Close()
+		return nil, fmt.Errorf("sync artist discography: iterate existing releases: %w", err)
+	}
 	rows.Close()
 
 	// Build the set of RGIDs present in this sync so we can drop only the rows