chore: Remove SSL cert handling - use external reverse proxy

- Nginx now listens on HTTP only (port 80)
- Remove SSL cert volume mounts from docker-compose
- Remove SSL troubleshooting sections
- Update docs to indicate SSL handled by Caddy/reverse proxy
- Simplify nginx.conf to remove HTTPS server block

README.md

@@ -37,16 +37,9 @@ cp .env.example .env
 # Edit .env with your values (see docs/SETUP-INFRASTRUCTURE.md)
 
 # 3. Create required directories
-mkdir -p docker/nginx/ssl
 mkdir -p frontend/public
 
-# 4. Generate SSL certificates (self-signed for local dev)
-openssl req -x509 -nodes -days 365 -newkey rsa:2048 \
-  -keyout docker/nginx/ssl/key.pem \
-  -out docker/nginx/ssl/cert.pem \
-  -subj "/CN=localhost"
-
-# 5. Start with Docker Compose
+# 4. Start with Docker Compose
 docker-compose up -d --build
 
 # 6. Initialize database (first time only)