fix(rescan): updateMediaItem re-derives format flags — force rescan reclassifies rows

internal/services/media_scanner.go

@@ -3152,10 +3152,36 @@ func (s *MediaScanner) updateMediaItem(ctx context.Context, existing database.Me
 	utils.ApplyMetadataOverrides(&params, existing)
 	params.MetadataOverrides = utils.MergeOverrides(existing.MetadataOverrides)
 
-	_, err = s.db.UpdateMediaItem(ctx, params)
+	if _, err = s.db.UpdateMediaItem(ctx, params); err != nil {
 		return err
 	}
 
+	// Format flags are file-derived facts, not user metadata: refresh them on
+	// every update so a force rescan (the admin's backfill tool) can
+	// reclassify rows created before a classifyFormatGroup arm existed.
+	// Mirrors the creation path above.
+	ext := strings.ToLower(filepath.Ext(path))
+	var epubIsFixedLayout bool
+	if ext == ".epub" {
+		isFixed, fixedErr := s.DetectFixedLayoutEPUB(path)
+		epubIsFixedLayout = fixedErr == nil && isFixed
+	}
+	formatGroup, isReflowable, hasFixedLayout := classifyFormatGroup(ext, epubIsFixedLayout)
+	mimeType := s.getMimeType(path)
+	if err := s.db.UpdateMediaItemFormatGroup(ctx, database.UpdateMediaItemFormatGroupParams{
+		ID:              existing.ID,
+		FormatGroup:     formatGroup,
+		FormatMimetype:  pgtype.Text{String: mimeType, Valid: mimeType != ""},
+		IsReflowable:    pgtype.Bool{Bool: isReflowable, Valid: true},
+		HasFixedLayout:  pgtype.Bool{Bool: hasFixedLayout, Valid: true},
+		TotalCharacters: pgtype.Int8{Int64: metadata.TotalCharacters, Valid: metadata.TotalCharacters > 0},
+		ChapterCount:    pgtype.Int4{Int32: metadata.ChapterCount, Valid: metadata.ChapterCount > 0},
+	}); err != nil {
+		fmt.Printf("Warning: failed to update format info for %s: %v\n", path, err)
+	}
+	return nil
+}
+
 // RescanMediaItem re-extracts metadata for a single media item and updates it.
 // It is the per-book rescan used by the Edit Metadata dialog and backfills
 // covers for items imported before the PDF render fallback existed.