feat(jobs): blob worker fans out to extract.pdf / extract.image

After creating a ref, the Node-side ingest.blob worker enqueues a
follow-up job for the Python void-workers (Plan 4) to OCR / extract
text. Other kinds (file) get no follow-up.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

lib/jobs/workers/blob.js

@@ -1,6 +1,7 @@
 import fs from 'node:fs/promises';
 import * as refs from '../../db/repos/refs.js';
 import { defaultStore } from '../../ingest/blob_store.js';
+import * as queue from '../queue.js';
 
 export const NAME = 'ingest.blob';
 
@@ -27,5 +28,12 @@ export async function handler(job) {
     blob_path: path,
     metadata: { sha, content_type, filename, size: buf.length, ...(meta.metadata || {}) }
   }, { kind: 'system', id: null });
+
+  // Plan 4: hand off to the Python void-workers for OCR / extraction.
+  if (kind === 'pdf') {
+    await queue.enqueue('extract.pdf', { ref_id: row.id, blob_path: path });
+  } else if (kind === 'image') {
+    await queue.enqueue('extract.image', { ref_id: row.id, blob_path: path });
+  }
   return { ref_id: row.id, sha };
 }