[codex] Maintenance quickstart and issue hygiene

[Zwc-11]

Summary

• Move the root design plan into docs/dev/ and update the README roadmap link.
• Make the documented terminal quickstart run the bundled calendar demo pipeline.
• Add a focused test for the calendar demo script path.
• Keep exactly two tracked issue files for unsupported XHR/WebSocket capture and real public sites.
• Add maintenance verification artifacts for the commands run in this session.

Validation

• npm install
• npm run dev -w @agentreplay/web with no backend, verified Demo mode
• pip install -e ".[dev]" from apps/api
• python -m app.scripts.demo calendar-demo from apps/api
• npm run test --workspaces --if-present
• python -m pytest apps/api/tests
• npm run lint
• npm run typecheck
• npm run test:e2e
• npm test
• npm audit --omit=dev report only

Notes

The calendar demo script artifact includes bundled demo data and a real-model DeepSeek summary because the local environment has DeepSeek configured. No dependency changes were made.