Enable ebook interactive search and job routing

Add support for interactive ebook searches and streamline search job routing. Key changes:

- RequestActionsDropdown: loosened status checks for search/adjust actions, route interactive search to an ebook-specific modal when the request is an ebook, and pass request.customSearchTerms to the ebook search modal.
- API: interactive-search-ebook route now supports two flows (direct ebook requests and audiobook sidecar ebook searches), updates validation logic, checks for existing child ebook requests only in sidecar mode, and improves logging. manual-search route now dispatches addSearchEbookJob for ebook requests and addSearchJob for audiobooks.
- RequestCard: removed manual/interactive search UI, related hooks and modal usage (interactive search is handled via the admin dropdown/modal now).

These changes enable direct ebook interactive search flows, prevent invalid searches based on request type/status, and ensure the correct background job is enqueued per request type.

src/app/api/requests/[id]/manual-search/route.ts

@@ -64,14 +64,20 @@ export async function POST(
         );
       }
 
-      // Trigger search job
+      // Trigger appropriate search job based on request type
       const jobQueue = getJobQueueService();
-      await jobQueue.addSearchJob(id, {
+      const audiobookData = {
         id: requestRecord.audiobook.id,
         title: requestRecord.audiobook.title,
         author: requestRecord.audiobook.author,
         asin: requestRecord.audiobook.audibleAsin || undefined,
-      });
+      };
+
+      if (requestRecord.type === 'ebook') {
+        await jobQueue.addSearchEbookJob(id, audiobookData);
+      } else {
+        await jobQueue.addSearchJob(id, audiobookData);
+      }
 
       // Update request status
       const updated = await prisma.request.update({