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>

docker/Caddyfile

@@ -0,0 +1,46 @@
+# Caddy reverse proxy configuration for Gitea MCP Remote
+#
+# This configuration provides:
+# - HTTPS termination with automatic certificates
+# - Reverse proxy to the Python MCP server
+# - Health check endpoint passthrough
+# - MCP protocol endpoint routing
+{
+    # Global options
+    email admin@example.com
+
+    # For local development, disable HTTPS redirect
+    # auto_https off
+}
+
+# Default site - adjust domain as needed
+:443, :80 {
+    # Health check endpoint - no authentication
+    handle /health {
+        reverse_proxy app:8080
+    }
+
+    # MCP protocol endpoint
+    handle /mcp {
+        reverse_proxy app:8080 {
+            # Pass through headers for MCP protocol
+            header_up X-Forwarded-Proto {scheme}
+            header_up X-Real-IP {remote_host}
+
+            # Ensure proper content type handling
+            flush_interval -1
+        }
+    }
+
+    # Fallback - proxy all other requests
+    handle {
+        reverse_proxy app:8080
+    }
+
+    # Logging
+    log {
+        output stdout
+        format console
+    }
+}
+}