trigger site rebuild after new user registration so profile pages exist immediately

bincio/serve/server.py

@@ -380,6 +380,9 @@ async def register(request: Request) -> JSONResponse:
     from bincio.render.cli import _write_root_manifest
     _write_root_manifest(dd)
 
+    # Rebuild site so the new user's profile pages exist immediately
+    _trigger_rebuild(handle)
+
     token = create_session(_get_db(), handle)
     resp = JSONResponse({"ok": True, "handle": handle})
     _set_session_cookie(resp, token)

docs/deployment/vps.md

@@ -264,9 +264,10 @@ server {
         try_files $uri $uri/ /activity/index.html;
     }
 
-    # Per-user profile pages: same fallback for new users.
+    # Per-user profile pages: fall back to the home page while the background
+    # rebuild (triggered automatically on registration) completes.
     location /u/ {
-        try_files $uri $uri/ =404;
+        try_files $uri $uri/ /index.html;
     }
 
     # Static files