Add multi-source ebook support and per-indexer categories

Introduces granular toggles for Anna's Archive and Indexer Search as ebook sources, updates settings UI to a three-section layout, and documents the new configuration. Adds per-indexer category configuration with separate tabs for audiobooks and ebooks, updates API routes and types for new settings, and ensures legacy config migration. Indexer grouping and file organization logic now support the new category structure and ebook source toggles.

src/app/api/admin/settings/ebook/route.ts

@@ -13,8 +13,8 @@ export async function PUT(request: NextRequest) {
   return requireAuth(request, async (req: AuthenticatedRequest) => {
     return requireAdmin(req, async () => {
       try {
-        // Parse request body
-        const { enabled, format, baseUrl, flaresolverrUrl } = await request.json();
+        // Parse request body - new structure with separate source toggles
+        const { annasArchiveEnabled, indexerSearchEnabled, format, baseUrl, flaresolverrUrl } = await request.json();
 
         // Validate format
         const validFormats = ['epub', 'pdf', 'mobi', 'azw3', 'any'];
@@ -25,8 +25,8 @@ export async function PUT(request: NextRequest) {
           );
         }
 
-        // Validate baseUrl (basic check)
-        if (baseUrl && !baseUrl.startsWith('http')) {
+        // Validate baseUrl (basic check) - only required if Anna's Archive is enabled
+        if (annasArchiveEnabled && baseUrl && !baseUrl.startsWith('http')) {
           return NextResponse.json(
             { error: 'Base URL must start with http:// or https://' },
             { status: 400 }
@@ -46,23 +46,32 @@ export async function PUT(request: NextRequest) {
         const configService = getConfigService();
 
         const configs = [
+          // New granular source toggles
           {
-            key: 'ebook_sidecar_enabled',
-            value: enabled ? 'true' : 'false',
+            key: 'ebook_annas_archive_enabled',
+            value: annasArchiveEnabled ? 'true' : 'false',
             category: 'ebook',
-            description: 'Enable e-book sidecar downloads from Annas Archive',
+            description: 'Enable e-book downloads from Anna\'s Archive',
           },
+          {
+            key: 'ebook_indexer_search_enabled',
+            value: indexerSearchEnabled ? 'true' : 'false',
+            category: 'ebook',
+            description: 'Enable e-book downloads via indexer search (Prowlarr)',
+          },
+          // General settings
           {
             key: 'ebook_sidecar_preferred_format',
             value: format || 'epub',
             category: 'ebook',
             description: 'Preferred e-book format',
           },
+          // Anna's Archive specific settings
           {
             key: 'ebook_sidecar_base_url',
             value: baseUrl || 'https://annas-archive.li',
             category: 'ebook',
-            description: 'Base URL for Annas Archive',
+            description: 'Base URL for Anna\'s Archive',
           },
           {
             key: 'ebook_sidecar_flaresolverr_url',