Fix trash button on repo when workspace has no local folder

clearRepoWorkspace was calling updateWorkspace to null out the repo
even when there was no local folder, leaving an empty workspace.
Now falls through to persistCodebase which correctly removes the
entire workspace when both cwd and repoUrl would be null.

Co-Authored-By: Paperclip <noreply@paperclip.ing>
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

ui/src/components/ProjectProperties.tsx

@@ -377,7 +377,7 @@ export function ProjectProperties({ project, onUpdate, onFieldUpdate, getFieldSa
         : "Delete this workspace repo?",
     );
     if (!confirmed) return;
-    if (primaryCodebaseWorkspace) {
+    if (primaryCodebaseWorkspace && hasLocalFolder) {
       updateWorkspace.mutate({
         workspaceId: primaryCodebaseWorkspace.id,
         data: { repoUrl: null, repoRef: null, defaultRef: null, sourceType: deriveSourceType(codebase.localFolder, null) },