- Add docs/installation.md covering prerequisites, port usage, Docker startup, local development setup, default accounts, first-run validation, and common setup issues.
- Link the installation guide from the project README and docs index.
- Point deployment documentation to the installation guide for first-time setup.
- Update AGENTS.md and progress documentation to include the new installation guide.
- Change the API default listen port from 3000 to 3100 and include the Docker frontend origin in default CORS.
- Point Vite's default API proxy, Docker API container port, and Nginx upstream to 3100.
- Keep Docker host ports on 4002 for web, 3002 for API, and 5433 for PostgreSQL.
- Update environment examples and documentation to remove stale localhost:3000 guidance.