✨ feat(scripts): add socket-specific development script

- add new "dev:socket" script to run with socket-only debug logs
- update "dev:stock" script to include both backend and socket debug namespaces

package.json

@@ -5,7 +5,8 @@
   "type": "module",
   "scripts": {
     "dev": "PORT=8080 node server",
-    "dev:stock": "PORT=8080 cross-env DEBUG=backend:* node server",
+    "dev:stock": "PORT=8080 cross-env DEBUG=backend:*,socket:* node server",
+    "dev:socket": "PORT=8080 cross-env DEBUG=socket:* node server",
     "build": "npm run build:client && npm run build:server && npm run build:api",
     "build:client": "vite build --outDir dist/client --manifest",
     "build:server": "vite build --ssr src/server/index.tsx --outDir dist/server",