Fix supabase directory structure - create writable .branches directory

default.nix

@@ -185,10 +185,18 @@ in
       description = "Supabase CLI Service";
       
       preStart = ''
-        # Copy supabase config if it exists in the app
+        # Clean slate - remove old content but keep the directory
+        rm -rf /var/lib/supabase/*
+        rm -rf /var/lib/supabase/.* 2>/dev/null || true
+        
+        # Copy supabase directory structure from the app
         if [ -d ${usda-vision-app}/opt/usda-vision/supabase ]; then
-          ${pkgs.rsync}/bin/rsync -av ${usda-vision-app}/opt/usda-vision/supabase/ /var/lib/supabase/
+          ${pkgs.rsync}/bin/rsync -av ${usda-vision-app}/opt/usda-vision/supabase/ /var/lib/supabase/supabase/
         fi
+        
+        # Create necessary directories for supabase
+        mkdir -p /var/lib/supabase/supabase/.branches
+        chmod -R 755 /var/lib/supabase
       '';
       
       serviceConfig = {