fix(directory-explorer): declare shouldCreateSelection in finalizeSelection

The variable was referenced at line 484 (the single-target create branch)
but never declared, so every non-clone add path (Add button, Cmd+Enter,
Open in Finder, mobile add) threw a ReferenceError that surfaced as a
'Failed to select directory' toast. Add the missing local declaration
matching the condition the original review intended: !isCloneMode &&
shouldCreateTarget && the target path equals the user-typed path.

packages/ui/src/components/session/DirectoryExplorerDialog.tsx

@@ -469,6 +469,7 @@ export const DirectoryExplorerDialog: React.FC<DirectoryExplorerDialogProps> = (
 
     setIsConfirming(true);
     try {
+      const shouldCreateSelection = !isCloneMode && shouldCreateTarget && normalizeDirectoryPath(target) === normalizeDirectoryPath(targetPath);
       if (isCloneMode) {
         const remoteUrl = cloneRemoteUrl.trim();
         if (!remoteUrl) {