Implement user soft-delete and improve search ranking

Adds soft-delete support for local users, including backend, API, and UI changes to allow admins to delete local users while preserving their requests. Updates user queries to exclude deleted users and allows username reuse for deleted accounts. Refines search and ranking logic for torrents: uses title-only queries for broader results, increases max results to 100, applies a minimum score threshold (30/100), and logs detailed ranking breakdowns. Updates the ranking algorithm to prioritize title/author match, adjusts scoring weights, and improves BookDate compatibility with Audiobookshelf by disabling rating-based features when unsupported. Enhances file copy operations for large files, improves metadata tagging, and updates documentation to reflect new search and ranking strategies.

src/lib/bookdate/helpers.ts

@@ -237,41 +237,57 @@ export async function getUserLibraryBooks(
   scope: 'full' | 'listened' | 'rated'
 ): Promise<LibraryBook[]> {
   try {
-    // Get user's Plex library configuration
     const configService = getConfigService();
-    const plexConfig = await configService.getPlexConfig();
+    const backendMode = await configService.getBackendMode();
 
-    if (!plexConfig.libraryId) {
-      console.warn('[BookDate] No Plex library ID configured');
-      return [];
+    // Early validation: audiobookshelf doesn't support ratings
+    if (backendMode === 'audiobookshelf' && scope === 'rated') {
+      console.warn('[BookDate] Audiobookshelf does not support ratings, falling back to full library');
+      scope = 'full';
     }
 
-    const plexLibraryId = plexConfig.libraryId;
+    // Get library ID based on backend mode
+    let libraryId: string;
+    if (backendMode === 'audiobookshelf') {
+      const absLibraryId = await configService.get('audiobookshelf.library_id');
+      if (!absLibraryId) {
+        console.warn('[BookDate] No Audiobookshelf library ID configured');
+        return [];
+      }
+      libraryId = absLibraryId;
+    } else {
+      // Plex mode
+      const plexConfig = await configService.getPlexConfig();
+      if (!plexConfig.libraryId) {
+        console.warn('[BookDate] No Plex library ID configured');
+        return [];
+      }
+      libraryId = plexConfig.libraryId;
+    }
 
-    // Check user type to determine query strategy for 'rated' scope
+    // Check user type for local admin detection (Plex-specific logic)
     const user = await prisma.user.findUnique({
       where: { id: userId },
       select: { plexId: true },
     });
-
     const isLocalAdmin = user?.plexId.startsWith('local-') ?? false;
 
-    // Build query filters based on scope and user type
-    let whereClause: any = { plexLibraryId };
+    // Build query filters
+    let whereClause: any = { plexLibraryId: libraryId };
     let takeLimit = 40;
 
-    if (scope === 'rated') {
+    // Apply rating filter only for Plex backend with rated scope
+    if (backendMode === 'plex' && scope === 'rated') {
       if (isLocalAdmin) {
-        // Local admin: Filter by cached ratings (these are their ratings)
+        // Local admin: Use cached ratings from system token
         whereClause.userRating = { not: null };
       } else {
-        // Plex-authenticated: Fetch more books to ensure we get 40 rated ones
-        // Don't filter by cached ratings - user's ratings may differ from system token
+        // OAuth user: Fetch more, filter after user rating enrichment
         takeLimit = 100;
       }
     }
 
-    // Query Plex library from database (cached structure, includes system token's cached ratings)
+    // Query library from database (same table for both backends)
     let cachedBooks = await prisma.plexLibrary.findMany({
       where: whereClause,
       orderBy: {
@@ -284,22 +300,32 @@ export async function getUserLibraryBooks(
         narrator: true,
         plexGuid: true,
         plexRatingKey: true,
-        userRating: true, // System token's cached ratings from scan
+        userRating: true,
       },
     });
 
-    // Enrich with user's personal ratings from Plex
-    const enrichedBooks = await enrichWithUserRatings(userId, cachedBooks);
+    // For Plex: Enrich with user's personal ratings
+    // For Audiobookshelf: Skip enrichment (no rating support)
+    if (backendMode === 'plex') {
+      const enrichedBooks = await enrichWithUserRatings(userId, cachedBooks);
 
-    // If scope is 'rated', filter to only books the user has actually rated
-    if (scope === 'rated') {
-      const ratedBooks = enrichedBooks.filter(book => book.rating != null);
-      // Limit to 40 for Plex users (local admin already limited in query)
-      return isLocalAdmin ? ratedBooks : ratedBooks.slice(0, 40);
+      // Filter to rated books if scope is 'rated'
+      if (scope === 'rated') {
+        const ratedBooks = enrichedBooks.filter(book => book.rating != null);
+        return isLocalAdmin ? ratedBooks : ratedBooks.slice(0, 40);
+      }
+
+      return enrichedBooks;
+    } else {
+      // Audiobookshelf: Map to LibraryBook without ratings
+      return cachedBooks.map(book => ({
+        title: book.title,
+        author: book.author,
+        narrator: book.narrator || undefined,
+        rating: undefined, // ABS doesn't support ratings
+      }));
     }
 
-    return enrichedBooks;
-
   } catch (error) {
     console.error('[BookDate] Error fetching library books:', error);
     return [];