Fix 'stream is not readable' error in SSE message handler

- Replace getRawBody with direct req.body usage since express.json() middleware already parses it
- Add debugging support with --inspect flag for dev scripts
- Add VS Code launch configurations for debugging

The issue was that getRawBody tried to read an already-consumed stream. Since express.json()
middleware is applied globally, we can directly use req.body instead.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

package.json

@@ -6,7 +6,8 @@
   "main": "dist/index.js",
   "scripts": {
     "start": "node dist/index.js",
-    "dev": "tsx watch src/index.ts",
+    "dev": "tsx watch --inspect src/index.ts",
+    "dev:break": "tsx --inspect-brk watch src/index.ts",
     "build": "tsc && npm run copy-static",
     "copy-static": "mkdir -p dist/static && cp -r src/static/* dist/static/",
     "lint": "eslint src/",