Folder picker: create a new folder (new automation, new chat)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

web/src/i18n/en.ts

@@ -553,6 +553,7 @@ export const en = {
   "jobs.tplMode": "Mode",
   "new.title": "New session",
   "new.directory": "Project directory",
+  "new.invalidFolderName": "Folder names cannot contain “/”.",
   "new.up": "Up",
   "new.noSubdirs": "No subdirectories",
   "new.model": "Model",