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/notifier/scheduler.go

@@ -16,8 +16,10 @@ import (
 // Releases already present in notifications_sent are excluded upstream by
 // GetUnnotifiedReleases, so this is idempotent across runs.
 //
-// If there are no unnotified releases the digest reports "no new missing
-// releases" and nothing is marked sent (there is nothing to mark).
+// If there are no unnotified releases nothing is sent (the caller's scheduler
+// is responsible for not spamming the operator with an empty digest). When
+// releases are present, each is marked sent so a subsequent run will not
+// re-notify it.
 //
 // uiBaseURL is the externally-reachable base URL of the Web UI, appended to the
 // digest so operators can jump to the dashboard.
@@ -42,7 +44,28 @@ func NotifyOnce(ctx context.Context, db *database.DB, sender Sender, cfg config.
 		})
 	}
 
-	message := FormatDigest(missing, uiBaseURL)
+	// Resolve human-readable artist names so the digest shows recognizable
+	// labels instead of opaque internal artist IDs. A lookup failure for a
+	// single artist must not abort the whole digest, so errors are ignored and
+	// that artist falls back to its ID via artistLabel.
+	names := make(map[string]string, len(missing))
+	for _, r := range unnotified {
+		if _, ok := names[r.ArtistID]; ok {
+			continue
+		}
+		settings, err := database.GetArtistSettings(db, r.ArtistID)
+		if err == nil && settings.Name != "" {
+			names[r.ArtistID] = settings.Name
+		}
+	}
+
+	message := FormatDigest(missing, uiBaseURL, names)
+	// Nothing to report: skip sending so the operator is not spammed with an
+	// empty digest on every cron fire. The startup fire likewise stays quiet
+	// until the first genuinely missing release appears.
+	if len(unnotified) == 0 {
+		return 0, nil
+	}
 	if err := sender.Send(ctx, message); err != nil {
 		return 0, fmt.Errorf("notifier: send digest: %w", err)
 	}