chore: consolidate env templates and remove Docker docs from master

- Merge .env.production.template into .env.example
- Remove Docker Deployment section from CLAUDE.md (now on docker branch)
- Update README.md to reference .env.example
- Update environment variable documentation

Co-Authored-By: Claude <noreply@anthropic.com>

CLAUDE.md

@@ -77,58 +77,6 @@ test("hello world", () => {
 });
 ```
 
-## Docker Deployment
-
-The application supports Docker deployment with single-port architecture and host-mounted database persistence.
-
-**Quick Start**:
-```bash
-# Create environment file
-cp .env.docker.example .env
-
-# Generate JWT secret
-openssl rand -base64 32  # Add to .env as JWT_SECRET
-
-# Start application
-docker-compose up -d --build
-
-# Access at http://localhost:3001
-```
-
-**Architecture**:
-- **Single Port**: Port 3001 serves both API (`/api/*`) and frontend (all other routes)
-- **Database Persistence**: SQLite database stored at `./data/award.db` on host
-- **Auto-initialization**: Database created from template on first startup
-- **Health Checks**: Built-in health monitoring at `/api/health`
-
-**Key Docker Files**:
-- `Dockerfile`: Multi-stage build using official Bun runtime
-- `docker-compose.yml`: Stack orchestration with volume mounts
-- `docker-entrypoint.sh`: Database initialization logic
-- `.env.docker.example`: Environment variable template
-- `DOCKER.md`: Complete deployment documentation
-
-**Environment Variables**:
-- `NODE_ENV`: Environment mode (default: production)
-- `PORT`: Application port (default: 3001)
-- `LOG_LEVEL`: Logging level (debug/info/warn/error)
-- `JWT_SECRET`: JWT signing secret (required, change in production!)
-- `VITE_APP_URL`: Your application's public URL
-- `ALLOWED_ORIGINS`: CORS allowed origins (comma-separated)
-
-**Database Management**:
-- Database location: `./data/award.db` (host-mounted volume)
-- Backups: `cp data/award.db data/award.db.backup.$(date +%Y%m%d)`
-- Reset: `docker-compose down -v && docker-compose up -d`
-
-**Important Notes**:
-- Database persists across container restarts/recreations
-- Frontend dependencies are reinstalled in container to ensure correct platform binaries
-- Uses custom init script (`src/backend/scripts/init-db.js`) with `bun:sqlite`
-- Architecture-agnostic (works on x86, ARM64, etc.)
-
-For detailed documentation, see `DOCKER.md`.
-
 ## Frontend
 
 Use HTML imports with `Bun.serve()`. Don't use `vite`. HTML imports fully support React, CSS, Tailwind.