feat: implement docker infrastructure (US-001)

- Add docker-compose.yml with postgres, redis, api, and web services
- Add multi-stage Dockerfile for API (Python 3.11)
- Add multi-stage Dockerfile for web (Node.js 20 + nginx)
- Add Makefile with common development commands
- Add .env.example with all required environment variables
- Add placeholder pyproject.toml and package.json for builds
- Configure health checks for all services
- Setup persistent volumes for postgres, redis, and repos
- Run services as non-root users

docs/README.md

@@ -1,20 +0,0 @@
-# Headquarter Documentation
-
-This directory contains architecture, development, and deployment documentation for the Headquarter platform.
-
-## Index
-
-- [Architecture](architecture.md) — Canonical system architecture, domain model, provider contracts, and security boundaries *(FN-019)*
-- [MVP Scope](mvp-scope.md) — MVP boundaries, user journeys, milestones, and dependency order *(FN-019)*
-- [Project Brief](project-brief.md) — High-level product context: what, why, who, and confirmed stack *(FN-019)*
-- [Development](development.md) — Local setup, prerequisites, and day-to-day commands *(FN-002)*
-- [Deployment](deployment.md) — Deployment assumptions, Portainer/Traefik skeleton, and operator guide *(FN-002)*
-
-## Reference
-
-- [Conversation Handoff](conversation-handoff.md) — Key architectural decisions, assumptions, and open loops from planning *(FN-019)*
-
-## Quick Links
-
-- [Root README](../README.md)
-- [Deployment Guide](deployment.md)