fix: add workspace to store synchronously before switching

When creating a workspace with async background operations, the
frontend can try to access the workspace before React processes
the state update. This causes a race condition where WorkspaceStore
throws 'must call addWorkspace() first'.

Fix by calling workspaceStore.addWorkspace() synchronously BEFORE
setting the selected workspace. This ensures the store knows about
the workspace immediately, regardless of when React batches the
state updates.

Author: ibetitsmike

src/browser/App.tsx

@@ -610,7 +610,13 @@ function AppInner() {
                           onProviderConfig={handleProviderConfig}
                           onReady={handleCreationChatReady}
                           onWorkspaceCreated={(metadata) => {
-                            // Add to workspace metadata map
+                            // IMPORTANT: Add workspace to store FIRST (synchronous) to ensure
+                            // the store knows about it before React processes the state updates.
+                            // This prevents race conditions where the UI tries to access the
+                            // workspace before the store has created its aggregator.
+                            workspaceStore.addWorkspace(metadata);
+
+                            // Add to workspace metadata map (triggers React state update)
                             setWorkspaceMetadata((prev) =>
                               new Map(prev).set(metadata.id, metadata)
                             );