feat: Add Docker infrastructure with Caddy and startup scripts (#25, #26)

Issue #25 - Docker multi-service infrastructure:
- Create docker/Dockerfile with multi-stage build, git support, port 8080
- Create docker/docker-compose.yml with app + Caddy services
- Create docker/Caddyfile for HTTPS termination and reverse proxy
- Create docker/.env.example with configuration template

Issue #26 - Startup scripts and tests:
- Create scripts/start.sh for production startup with env validation
- Create scripts/healthcheck.sh for Docker health checks
- Add health endpoint tests to test_mcp_endpoints.py
- Fix middleware order (HealthCheckBypass must wrap BearerAuth)
- Fix pyproject.toml testpaths to use 'tests' directory
- Update test_config.py for new defaults (0.0.0.0:8080)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

pyproject.toml

@@ -60,7 +60,7 @@ where = ["src"]
 
 [tool.pytest.ini_options]
 asyncio_mode = "auto"
-testpaths = ["src/gitea_mcp_remote/tests"]
+testpaths = ["tests"]
 python_files = ["test_*.py"]
 python_classes = ["Test*"]
 python_functions = ["test_*"]