Refactor indexer management and improve search logic

Refactors admin settings to use a new IndexersTab and card-based indexer management UI, supporting category selection and improved configuration. Updates backend and API routes to handle indexer categories, propagate ASIN for better search scoring, and group indexers by categories to optimize Prowlarr searches. Enhances documentation to clarify non-terminal request matching and auto-completion behavior. Adds new reusable components for indexer management and category selection.

src/lib/services/job-queue.service.ts

@@ -37,6 +37,7 @@ export interface SearchIndexersPayload extends JobPayload {
     id: string;
     title: string;
     author: string;
+    asin?: string; // Optional ASIN for runtime-based size scoring
   };
 }
 
@@ -441,7 +442,7 @@ export class JobQueueService {
   /**
    * Add search indexers job
    */
-  async addSearchJob(requestId: string, audiobook: { id: string; title: string; author: string }): Promise<string> {
+  async addSearchJob(requestId: string, audiobook: { id: string; title: string; author: string; asin?: string }): Promise<string> {
     return await this.addJob(
       'search_indexers',
       {