feat: migrate admin endpoints to get_admin_db (BYPASSRLS) before RLS switch

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/app/api/endpoints/admin_dashboard.py

@@ -3,7 +3,7 @@ from fastapi import APIRouter, Depends
 from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy import select, func
 
-from app.core.database import get_db
+from app.core.admin_database import get_admin_db
 from app.models.user import User
 from app.models.subscription import Subscription
 from app.models.tree import Tree
@@ -16,7 +16,7 @@ router = APIRouter(prefix="/admin/dashboard", tags=["admin-dashboard"])
 
 @router.get("/metrics", response_model=DashboardMetrics)
 async def get_dashboard_metrics(
-    db: Annotated[AsyncSession, Depends(get_db)],
+    db: Annotated[AsyncSession, Depends(get_admin_db)],
     current_user: Annotated[User, Depends(require_admin)],
 ):
     """Get platform overview metrics."""
@@ -45,7 +45,7 @@ async def get_dashboard_metrics(
 
 @router.get("/activity", response_model=list[ActivityEntry])
 async def get_dashboard_activity(
-    db: Annotated[AsyncSession, Depends(get_db)],
+    db: Annotated[AsyncSession, Depends(get_admin_db)],
     current_user: Annotated[User, Depends(require_admin)],
 ):
     """Get recent audit log entries for activity feed."""