chore(ai): add smoke test script (agent)

- Adds `scripts/agent/smoke-test.mjs` to verify key flows:
  - Local relay setup
  - Local HTTP server (npx serve)
  - `NostrClient` integration (Node.js)
  - Frontend UI verification (Playwright)
  - Login, Video Publish, DM Decryption
- Adds `test:smoke` script to `package.json`
- Generates reports in `artifacts/`

Co-authored-by: PR0M3TH3AN <[email protected]>

scripts/agent/smoke-test.mjs

@@ -1,3 +1,7 @@
+/**
+ * Smoke Test Script (Agent)
+ * Verifies key flows: login, relay connect, video post, DM decrypt.
+ */
 
 import './setup-test-env.js';
 import { startRelay } from './load-test-relay.mjs';