Exports and every other native-picker action 403'd with "Invalid or expired desktop authorization" whenever Tauri and the backend resolved different data directories — a dev backend spawned without the OMNIVOICE_* env, a custom data folder, or portable mode. Tauri now takes the directory the running backend advertises, so the two processes cannot disagree, falling back to its own resolution when the backend is unreachable. One resolver covers all six capability kinds. Also decodes JSON escapes when reading that field, which Windows paths depend on, requires an absolute path so a relative data dir cannot recreate the same split, and keeps the 403 and its log line free of filesystem paths. Fixes#1781.
