feat: hide dotfiles in file explorer (#1516)

* feat: hide dotfiles in file explorer

* refactor: rename to "hidden files" and read flag from store

Rename the explorer dotfile toggle to show-semantics "hidden files"
so copy and code share one cross-platform vocabulary, and stop
prop-drilling the flag now that it lives in the panel store.

- explorerShowHiddenFiles (default true) replaces explorerHideDotFiles;
  i18n keys + translations switched from "dotfiles" to "hidden files"
- imperative helpers read usePanelStore.getState() instead of taking
  the flag as a parameter; flag stays threaded only through the
  reactive tree-row render path
- drop dead usePanelState exposure; collapse migration double-guard

* fix: address Greptile review on hidden-file path matching

- isHiddenExplorerPath no longer treats ".." segments as hidden
  (only "." was exempt before); add tests for ".." and "../sibling"
- assert the showHiddenFiles i18n key alongside hideHiddenFiles

---------

Co-authored-by: Mohamed Boudra <boudra.moha@gmail.com>

packages/app/src/i18n/resources/ar.ts

@@ -355,9 +355,12 @@ export const ar: TranslationResources = {
         retry: "أعد المحاولة",
         refresh: "تحديث الملفات",
         refreshing: "تحديث الملفات",
+        hideHiddenFiles: "إخفاء الملفات المخفية",
+        showHiddenFiles: "إظهار الملفات المخفية",
       },
       empty: {
         noFiles: "لا توجد ملفات",
+        noVisibleFiles: "لا توجد ملفات مرئية",
       },
       states: {
         unavailable: "Workspace غير متوفر",