fix: address code review findings

- Create README.md with project overview, quick start, Docker deployment, CI/CD info
- Update CLAUDE.md with Deployment section
- Fix cmd/api/main.go to use REDIS_ADDR env var with fallback
- Fix Dockerfile to use golang:1.22-alpine instead of golang:1.26-alpine
- Fix .gitea/workflows/deploy.yml to include Docker registry prefix in image tags

CLAUDE.md

@@ -76,6 +76,35 @@ go fmt ./...
 go vet ./...
 ```
 
+## Deployment
+
+### Docker Deployment
+
+The project uses a multi-stage Dockerfile:
+- **Builder stage**: `golang:1.22-alpine` to build `api` and `cron` binaries
+- **Runtime stage**: `alpine:latest` with minimal footprint (~27MB)
+
+### Docker Compose
+
+The `docker-compose.yml` includes:
+- `api` service: Go HTTP server on port 8080
+- `cron` service: Go cron binary for reference data updates and station status detection
+- `postgres`: PostgreSQL 15-alpine with `postgres_data` volume
+- `redis`: Redis 7-alpine with `redis_data` volume
+- `watchtower`: nickfedor/watchtower for automatic container updates (interval: 60s)
+
+### CI/CD Pipeline
+
+Gitea Actions workflow (`.gitea/workflows/deploy.yml`) provides:
+- Checkout code
+- Setup Go 1.22+
+- Go modules cache
+- Lint with golangci-lint v1.54.2
+- Run tests with race detector: `go test -v -race ./...`
+- Docker Buildx setup
+- Docker login to registry
+- Build and push Docker image with tags: `latest` and commit SHA
+
 ### API Endpoints (from specification)
 
 - `GET /v1/cities?query=` — City autocomplete