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

dockerfiles/drawio-mcp/Dockerfile

@@ -1,13 +1,16 @@
 FROM node:22-alpine
 
+# Install pnpm
+RUN npm install -g pnpm
+
 WORKDIR /app
 
-COPY package.json package-lock.json* ./
+COPY package.json pnpm-lock.yaml ./
 
-RUN npm ci
+RUN pnpm install --frozen-lockfile
 
 COPY . .
 
-RUN npm run build
+RUN pnpm run build
 
-CMD ["node", "dist/index.js"]
+CMD ["node", "build/index.js"]