chore: split Vercel deployment for docs and demo

- Create apps/site/vercel.json for standalone docs deployment
- Update root vercel.json rewrites (remove /docs/ exclusion)
- Update build:vercel to only build web app (no docs merge)

Co-authored-by: hotlong <50353452+hotlong@users.noreply.github.com>

Author: Copilot

apps/site/vercel.json

@@ -0,0 +1,4 @@
+{
+  "$schema": "https://openapi.vercel.sh/vercel.json",
+  "cleanUrls": true
+}

package.json

@@ -20,7 +20,7 @@
     "dev:all": "concurrently -n api,web,site -c blue,green,yellow \"pnpm objectstack:serve\" \"pnpm web:dev\" \"pnpm site:dev\"",
     "start": "pnpm objectstack:serve",
     "build": "turbo run build",
-    "build:vercel": "turbo run build && cp -r apps/site/out apps/web/dist/docs",
+    "build:vercel": "turbo run build --filter=@objectos/web...",
     "test": "turbo run test --concurrency=3",
     "lint": "turbo run lint",
     "clean": "turbo run clean",

vercel.json

@@ -12,6 +12,6 @@
   },
   "rewrites": [
     { "source": "/api/v1/(.*)", "destination": "/api" },
-    { "source": "/((?!api/|docs/).*)", "destination": "/index.html" }
+    { "source": "/((?!api/).*)", "destination": "/index.html" }
   ]
 }