feat(TRUEREF-0009): implement indexing pipeline and job queue

Implements the end-to-end indexing pipeline with a SQLite-backed job
queue, startup recovery, and REST API endpoints for job status.

- IndexingPipeline: orchestrates crawl → parse → atomic replace → embed
  → repo stats update with progress tracking at each stage
- JobQueue: sequential SQLite-backed queue (no external broker), deduplicates
  active jobs per repository, drains queued jobs on startup
- startup.ts: stale job recovery (running→failed), repo state reset, singleton
  initialization wired from hooks.server.ts
- GET /api/v1/jobs with repositoryId/status/limit filtering
- GET /api/v1/jobs/[id] single job lookup
- hooks.server.ts: initializes DB and pipeline on server start
- 18 unit tests covering queue, pipeline stages, recovery, and atomicity

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/routes/api/v1/jobs/[id]/+server.ts

@@ -0,0 +1,34 @@
+/**
+ * GET /api/v1/jobs/:id — retrieve a single indexing job by ID.
+ */
+
+import { json } from '@sveltejs/kit';
+import type { RequestHandler } from './$types';
+import { getClient } from '$lib/server/db/client.js';
+import { JobQueue } from '$lib/server/pipeline/job-queue.js';
+import { handleServiceError, NotFoundError } from '$lib/server/utils/validation.js';
+
+export const GET: RequestHandler = ({ params }) => {
+	try {
+		const db = getClient();
+		const queue = new JobQueue(db);
+
+		const job = queue.getJob(params.id);
+		if (!job) throw new NotFoundError(`Job ${params.id} not found`);
+
+		return json({ job });
+	} catch (err) {
+		return handleServiceError(err);
+	}
+};
+
+export const OPTIONS: RequestHandler = () => {
+	return new Response(null, {
+		status: 204,
+		headers: {
+			'Access-Control-Allow-Origin': '*',
+			'Access-Control-Allow-Methods': 'GET, OPTIONS',
+			'Access-Control-Allow-Headers': 'Content-Type, Authorization'
+		}
+	});
+};