feat(TRUEREF-0002): implement repository management service and REST API

Add RepositoryService with full CRUD, ID resolution helpers, input
validation, six SvelteKit API routes (GET/POST /api/v1/libs,
GET/PATCH/DELETE /api/v1/libs/:id, POST /api/v1/libs/:id/index), and
37 unit tests covering all service operations.

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

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

@@ -0,0 +1,68 @@
+/**
+ * GET    /api/v1/libs/:id  — get a single repository
+ * PATCH  /api/v1/libs/:id  — update repository metadata
+ * DELETE /api/v1/libs/:id  — delete a repository
+ */
+import { json } from '@sveltejs/kit';
+import type { RequestHandler } from './$types';
+import { getClient } from '$lib/server/db/client';
+import { RepositoryService } from '$lib/server/services/repository.service';
+import { handleServiceError } from '$lib/server/utils/validation';
+
+function getService() {
+	return new RepositoryService(getClient());
+}
+
+export const GET: RequestHandler = ({ params }) => {
+	try {
+		const service = getService();
+		const id = decodeURIComponent(params.id);
+		const repo = service.get(id);
+		if (!repo) {
+			return json({ error: 'Repository not found', code: 'NOT_FOUND' }, { status: 404 });
+		}
+		const versions = service.getVersions(id);
+		return json({ ...repo, versions });
+	} catch (err) {
+		return handleServiceError(err);
+	}
+};
+
+export const PATCH: RequestHandler = async ({ params, request }) => {
+	try {
+		const service = getService();
+		const id = decodeURIComponent(params.id);
+		const body = await request.json();
+		const updated = service.update(id, {
+			title: body.title,
+			description: body.description,
+			branch: body.branch,
+			githubToken: body.githubToken
+		});
+		return json(updated);
+	} catch (err) {
+		return handleServiceError(err);
+	}
+};
+
+export const DELETE: RequestHandler = ({ params }) => {
+	try {
+		const service = getService();
+		const id = decodeURIComponent(params.id);
+		service.remove(id);
+		return new Response(null, { status: 204 });
+	} 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, PATCH, DELETE, OPTIONS',
+			'Access-Control-Allow-Headers': 'Content-Type, Authorization'
+		}
+	});
+};