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.test.ts

@@ -224,7 +224,10 @@ describe("translation resources", () => {
     expect(en.importSession.status.connectHost).toBe("Connect to a host to import sessions");
     expect(en.importSession.actions.refresh).toBe("Refresh sessions");
     expect(en.workspace.fileExplorer.sort.name).toBe("Name");
+    expect(en.workspace.fileExplorer.actions.hideHiddenFiles).toBe("Hide hidden files");
+    expect(en.workspace.fileExplorer.actions.showHiddenFiles).toBe("Show hidden files");
     expect(en.workspace.fileExplorer.empty.noFiles).toBe("No files");
+    expect(en.workspace.fileExplorer.empty.noVisibleFiles).toBe("No visible files");
     expect(en.workspace.setup.status.running).toBe("Running");
     expect(en.workspace.setup.empty.noCommands).toBe("No setup commands ran for this workspace.");
     expect(en.workspace.browser.unavailable.title).toBe("Browser is desktop-only");