Add MCP server authentication and update Docker configuration

This commit implements several key improvements to the GeoGuessr MCP server:

## MCP Server Authentication
- Add Bearer token authentication for MCP server access control
- New middleware in src/geoguessr_mcp/middleware/auth.py
- Configuration via MCP_AUTH_ENABLED and MCP_API_KEYS environment variables
- Support for multiple API keys (comma-separated)
- Optional authentication - can be disabled for trusted deployments
- Clients connect using Authorization: Bearer YOUR_API_KEY header

## Docker Configuration Updates
- Update to use official pre-built image: nyxiumyuuki/geoguessr-mcp:latest
- Remove DOCKER_USERNAME and IMAGE_TAG from environment variables
- Simplify docker-compose.yml and docker-compose.prod.yml
- Remove healthcheck configuration (not necessary for the deployment)

## Deployment Improvements
- Move deploy.sh to scripts/deploy.sh for better organization
- Update deploy.sh to use official Docker image
- Add authentication validation in deployment script
- Improve deployment logging and error messages

## Documentation Updates
- Update README.md with authentication configuration examples
- Add MCP server authentication section with setup instructions
- Update environment variables table
- Simplify deployment instructions
- Update CLAUDE.md with new authentication architecture
- Add .env.example configuration for MCP authentication

## Technical Details
- Authentication middleware integrates with FastMCP's Starlette ASGI app
- Middleware validates Bearer tokens on all requests except /health
- Logs authentication attempts and failures
- Returns proper 401/403 HTTP status codes
- Validates configuration on startup to prevent misconfiguration

Resolves TODO items:
- [x] Fix Docker username in compose files and env vars
- [x] Add authentication to MCP server to allow access only to specific users

src/geoguessr_mcp/main.py

@@ -11,6 +11,7 @@ import sys
 from mcp.server.fastmcp import FastMCP
 
 from .config import settings
+from .middleware import AuthenticationMiddleware
 from .monitoring import endpoint_monitor
 from .tools import register_all_tools
 
@@ -58,6 +59,12 @@ mcp = FastMCP(
 # Register all tools
 services = register_all_tools(mcp)
 
+# Add authentication middleware if needed
+if settings.MCP_AUTH_ENABLED:
+    logger.info("Registering authentication middleware")
+    # Add middleware to the underlying ASGI app
+    mcp.app.add_middleware(AuthenticationMiddleware)
+
 
 async def start_background_tasks():
     """Start background monitoring tasks."""
@@ -79,11 +86,17 @@ def main():
         f"with {settings.TRANSPORT} transport"
     )
 
+    if settings.MCP_AUTH_ENABLED:
+        api_key_count = len(settings.get_api_keys())
+        logger.info(f"MCP server authentication is ENABLED with {api_key_count} API key(s)")
+    else:
+        logger.warning("MCP server authentication is DISABLED - server is publicly accessible")
+
     if settings.DEFAULT_NCFA_COOKIE:
-        logger.info("Default authentication cookie configured from environment")
+        logger.info("Default GeoGuessr authentication cookie configured from environment")
     else:
         logger.warning(
-            "No default authentication cookie set. " "Users will need to login or provide a cookie."
+            "No default GeoGuessr authentication cookie set. " "Users will need to login or provide a cookie."
         )
 
     # Run the server