feat: add integration tests for control plane using workerd runtime (#73)

Adds 14 integration tests that run inside the real workerd runtime via
@cloudflare/vitest-pool-workers, validating Worker boot, routing, HMAC
auth, D1 database operations, and Durable Objects with SQLite storage.

Tests run offline with no cloud credentials — miniflare provides local
D1 (SQLite), KV, and DO implementations.

isolatedStorage is disabled due to workers-sdk#11031 (SQLite WAL files
break the storage snapshot assertions). D1 isolation is achieved via
beforeEach cleanup instead.

Author: ColeMurray

.github/workflows/ci.yml

@@ -130,6 +130,12 @@ jobs:
       - name: Run control-plane tests
         run: npm test -w @open-inspect/control-plane
 
+      - name: Install workerd runtime dependency
+        run: sudo apt-get update && sudo apt-get install -y libc++1
+
+      - name: Run control-plane integration tests
+        run: npm run test:integration -w @open-inspect/control-plane
+
       - name: Run web tests
         run: npm test -w @open-inspect/web