Add MCP Schema Endpoint for API Discovery

- Implemented `/mcp` endpoint to expose server capabilities
- Created `src/mcp/schema.ts` with comprehensive tool and resource definitions
- Updated README.md with MCP Schema documentation
- Modified security middleware to allow unauthenticated access to schema endpoint
- Included detailed tool descriptions for list_devices, control, and event subscription

src/security/index.ts

@@ -127,8 +127,8 @@ export class TokenManager {
 
 // Request validation middleware
 export function validateRequest(req: Request, res: Response, next: NextFunction) {
-    // Skip validation for health endpoint
-    if (req.path === '/health') {
+    // Skip validation for health and MCP schema endpoints
+    if (req.path === '/health' || req.path === '/mcp') {
         return next();
     }