🤖 Fix workspace deletion UI crash with layered null checks

- Primary fix: Handle null metadata in onMetadata subscription (delete from map)
- Defense: Add null check to filter in sortedWorkspacesByProject
- Safety: Add null guard in metadata comparison function

Prevents crash when deleting workspace by ensuring null metadata
never pollutes the state Map or reaches comparison logic.

Author: ammar-agent

src/App.tsx

@@ -419,7 +419,7 @@ function AppInner() {
         // Transform Workspace[] to FrontendWorkspaceMetadata[] using workspace ID
         const metadataList = config.workspaces
           .map((ws) => (ws.id ? workspaceMetadata.get(ws.id) : undefined))
-          .filter((meta): meta is FrontendWorkspaceMetadata => meta !== undefined);
+          .filter((meta): meta is FrontendWorkspaceMetadata => meta !== undefined && meta !== null);
 
         // Sort by recency
         metadataList.sort((a, b) => {
@@ -440,7 +440,7 @@ function AppInner() {
           // Check both ID and name to detect renames
           return a.every((metadata, i) => {
             const bMeta = b[i];
-            if (!bMeta) return false;
+            if (!bMeta || !metadata) return false; // Null-safe
             return metadata.id === bMeta.id && metadata.name === bMeta.name;
           });
         })

src/hooks/useWorkspaceManagement.ts

@@ -52,10 +52,15 @@ export function useWorkspaceManagement({
   // Subscribe to metadata updates (for create/rename/delete operations)
   useEffect(() => {
     const unsubscribe = window.api.workspace.onMetadata(
-      (event: { workspaceId: string; metadata: FrontendWorkspaceMetadata }) => {
+      (event: { workspaceId: string; metadata: FrontendWorkspaceMetadata | null }) => {
         setWorkspaceMetadata((prev) => {
           const updated = new Map(prev);
-          updated.set(event.workspaceId, event.metadata);
+          if (event.metadata === null) {
+            // Workspace deleted - remove from map
+            updated.delete(event.workspaceId);
+          } else {
+            updated.set(event.workspaceId, event.metadata);
+          }
           return updated;
         });
       }