feat: add MCP server validation script and fix drawio-mcp

- Add validate-mcp.sh script to test MCP servers with protocol messages
- Fix drawio-mcp Dockerfile to use pnpm and correct build directory
- Update drawio-mcp to use build/ instead of dist/
- Validate penpot-mcp, context7-mcp, docker-mcp, drawio-mcp working

docker-compose.yml

@@ -422,12 +422,11 @@ services:
     image: kneldevstack-aimiddleware-drawio-mcp
     build:
       context: ./vendor/drawio-mcp-server
-      dockerfile: Dockerfile
+      dockerfile: ../../dockerfiles/drawio-mcp/Dockerfile
     container_name: kneldevstack-aimiddleware-drawio-mcp
     restart: unless-stopped
     environment:
       - DRAWIO_URL=${DRAWIO_URL:-https://app.diagrams.net}
-    command: ["npx", "-y", "drawio-mcp-server"]
     profiles:
       - dev