Add e-book sidecar integration and improve request handling

Introduces optional e-book sidecar downloads from Anna's Archive, including admin UI, settings API, FlareSolverr integration, and documentation. Enhances request creation logic to prevent duplicate downloads by checking for 'downloaded' and 'available' statuses, updates UI to reflect processing state, and adds SABnzbd support to download and cleanup flows. Also updates ranking algorithm documentation and improves cache invalidation for recent requests.

src/app/api/admin/settings/test-download-client/route.ts

@@ -24,6 +24,8 @@ export async function POST(request: NextRequest) {
           localPath,
         } = await request.json();
 
+        console.log('[TestDownloadClient] Received request:', { type, url, hasUsername: !!username, hasPassword: !!password });
+
         if (!type || !url) {
           return NextResponse.json(
             { success: false, error: 'Type and URL are required' },
@@ -59,6 +61,7 @@ export async function POST(request: NextRequest) {
         let version: string | undefined;
 
         if (type === 'qbittorrent') {
+          console.log('[TestDownloadClient] Testing qBittorrent connection');
           if (!username || !actualPassword) {
             return NextResponse.json(
               { success: false, error: 'Username and password are required for qBittorrent' },
@@ -74,6 +77,7 @@ export async function POST(request: NextRequest) {
             disableSSLVerify || false
           );
         } else if (type === 'sabnzbd') {
+          console.log('[TestDownloadClient] Testing SABnzbd connection');
           if (!actualPassword) {
             return NextResponse.json(
               { success: false, error: 'API key (password) is required for SABnzbd' },