Add refresh from source for entries and whole lists

- Every provider can look an entry up again by its ID (TMDB, TheTVDB,
  IGDB, Deezer, MusicBrainz, Wikipedia); search and lookup share parsing
- POST /api/items/{id}/refresh re-applies title, subtitle, year,
  description, link, details and artwork. Kept: the "why" note, rank,
  theater production/venue/cast and a theater entry's year, the Deezer
  preview match. Empty source fields don't erase existing values
- New items.image_custom column (migration 4; existing uploads marked)
  records artwork the owner chose; refresh keeps it unless asked
- Refused for custom lists and hand-added entries; entries the source
  dropped are reported, and a refresh whose title shares no words with
  the current one is rejected as a likely bad ID
- Editor: refresh button per row (asks about the owner's own artwork),
  and "Refresh all" with a confirm step, replace-my-art checkbox,
  progress with Stop, and a summary of problems

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/server/api.go

@@ -131,6 +131,9 @@ type itemInput struct {
 	Extra       map[string]string `json:"extra"`
 	ImageURL    string            `json:"imageUrl"`
 	ClearImage  bool              `json:"clearImage"`
+	// CustomArt marks an added entry's image as the owner's own choice
+	// rather than the search result's.
+	CustomArt bool `json:"customArt"`
 
 	// Only used when adding.
 	Provider   string `json:"provider"`
@@ -196,7 +199,7 @@ func (s *Server) apiAddItem(w http.ResponseWriter, r *http.Request) {
 		if err != nil {
 			warning = "Added without artwork: " + err.Error()
 		} else {
-			it.Image, it.ImageSource = name, res.ImageURL
+			it.Image, it.ImageSource, it.CustomArt = name, res.ImageURL, in.CustomArt
 		}
 	}
 	s.matchDeezer(ctx, list.Category, &it)
@@ -273,8 +276,10 @@ func (s *Server) apiUpdateItem(w http.ResponseWriter, r *http.Request) {
 	if in.Extra != nil {
 		it.Extra = in.Extra
 	}
+	// Removing art or swapping it in by hand makes it the owner's choice,
+	// which a refresh leaves alone unless asked.
 	if in.ClearImage {
-		it.Image, it.ImageSource = "", ""
+		it.Image, it.ImageSource, it.CustomArt = "", "", true
 	}
 	if url := strings.TrimSpace(in.ImageURL); url != "" && url != cur.ImageSource {
 		name, err := s.fetchImage(ctx, url)
@@ -282,7 +287,7 @@ func (s *Server) apiUpdateItem(w http.ResponseWriter, r *http.Request) {
 			s.writeErr(w, store.ValidationError{Msg: "Couldn't use that image: " + err.Error()})
 			return
 		}
-		it.Image, it.ImageSource = name, url
+		it.Image, it.ImageSource, it.CustomArt = name, url, true
 	}
 	if it.Title != cur.Title || it.Subtitle != cur.Subtitle || it.Extra["deezer"] == "" {
 		if l, err := s.store.ListByID(ctx, it.ListID); err == nil {
@@ -335,7 +340,7 @@ func (s *Server) apiUploadItemImage(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	it := cur
-	it.Image, it.ImageSource = name, "upload"
+	it.Image, it.ImageSource, it.CustomArt = name, "upload", true
 	saved, err := s.store.UpdateItem(ctx, it)
 	if err != nil {
 		s.releaseImage(ctx, name)