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/web/handlers.go

@@ -3,6 +3,7 @@ package web
 import (
 	"context"
 	"embed"
+	"errors"
 	"fmt"
 	"html/template"
 	"net/http"
@@ -238,6 +239,14 @@ func (s *Server) ignoreOrRestore(w http.ResponseWriter, r *http.Request) {
 
 	ignored := action == "ignore"
 	if err := database.SetReleaseIgnored(s.db, rgid, ignored); err != nil {
+		// A 0-rows-affected error means the release was already removed by a
+		// concurrent re-sync (it disappeared from MusicBrainz). That is benign:
+		// redirect back rather than surfacing a 500 for a now-nonexistent row.
+		var notFoundErr error = database.ErrReleaseNotFound
+		if errors.Is(err, notFoundErr) {
+			http.Redirect(w, r, "/artist/"+id, http.StatusSeeOther)
+			return
+		}
 		http.Error(w, fmt.Sprintf("failed to set ignored: %v", err), http.StatusInternalServerError)
 		return
 	}