test(integration): add real-stack integration test suite with PGlite

- PGlite (in-memory WASM Postgres) hosted in a child process, exposed
  via TCP socket; real migrations applied with prisma migrate deploy
- Vitest harness (vitest.integration.config.ts, global-setup spawns
  PGlite + built Nuxt server, per-test TRUNCATE, factories, cookie-jar
  API client); no mocks, zero production code changes
- 50 tests across auth, hunt, team, submit, review, showcase, diashow
  incl. SuperJSON envelope check; *.itest.ts keeps bun test untouched
- CI: parallel unit + integration jobs in .github/workflows/test.yml
- tests/ covered by nuxt typecheck via tests/tsconfig.json reference

tests/integration/pglite-host.mjs

@@ -0,0 +1,26 @@
+// Hosts an in-memory PGlite database behind a TCP socket speaking the
+// Postgres wire protocol. Spawned by global-setup.ts as a child process.
+//
+// Deliberately plain .mjs so it can run under a bare `node` with no
+// TS loader, and deliberately never calls db.close()/server.stop():
+// under Bun, PGlite teardown triggers an Emscripten exit(99) which would
+// kill the process with a non-zero code. Cleanup happens via SIGTERM/SIGKILL.
+import { PGlite } from '@electric-sql/pglite';
+import { PGLiteSocketServer } from '@electric-sql/pglite-socket';
+
+const db = new PGlite();
+await db.waitReady;
+
+const server = new PGLiteSocketServer({
+  db,
+  port: 0,
+  host: '127.0.0.1',
+  maxConnections: 20
+});
+await server.start();
+
+const [host, port] = server.getServerConn().split(':');
+console.log(`PGLITE_READY postgresql://postgres@${host}:${port}/postgres`);
+
+process.on('SIGTERM', () => process.exit(0));
+process.on('SIGINT', () => process.exit(0));