feat: add MCP server package for npx distribution

- Self-contained MCP server with embedded HTTP server
- Real-time browser preview via draw.io iframe
- Tools: start_session, display_diagram, edit_diagram, get_diagram, export_diagram
- Port retry limit (6002-6020) and session TTL cleanup (1 hour)
- Published as @next-ai-drawio/mcp-server on npm

packages/mcp-server/tsconfig.json

@@ -0,0 +1,19 @@
+{
+    "compilerOptions": {
+        "target": "ES2022",
+        "module": "Node16",
+        "moduleResolution": "Node16",
+        "outDir": "./dist",
+        "rootDir": "./src",
+        "strict": true,
+        "esModuleInterop": true,
+        "skipLibCheck": true,
+        "forceConsistentCasingInFileNames": true,
+        "declaration": true,
+        "declarationMap": true,
+        "sourceMap": true,
+        "resolveJsonModule": true
+    },
+    "include": ["src/**/*"],
+    "exclude": ["node_modules", "dist"]
+}