Implement Supabase-first me bootstrap

routers/me/bootstrap_router.py

@@ -0,0 +1,18 @@
+from typing import Any, Dict
+
+from fastapi import APIRouter, Depends, HTTPException
+
+from modules.auth.supabase_bearer import SupabaseBearer
+from modules.database.services.bootstrap_service import build_bootstrap_response
+
+router = APIRouter()
+auth_scheme = SupabaseBearer()
+
+
+@router.get("/bootstrap")
+async def get_me_bootstrap(credentials: Dict[str, Any] = Depends(auth_scheme)) -> Dict[str, Any]:
+    """Authenticated Supabase-first session/onboarding bootstrap contract."""
+    try:
+        return build_bootstrap_response(credentials)
+    except ValueError as exc:
+        raise HTTPException(status_code=403, detail=str(exc)) from exc