feat(ui): add a desktop panel rail to each sidebar

Each side stack hosts a Vue rail listing its panels; selecting one opens it
through PanelChrome. The shell owns one Vue runtime and Pinia instance, and a
panel store mirrors each side's panels from the DOM. The rail hides with its
stack, in Cockpit, clean view and recording, and on phones. Panels without a
catalog entry get a generic item, and Data Layers leaves the rail while the
f shortcut hides it.

scripts/i18n.mjs

@@ -433,6 +433,7 @@ function sourceFiles() {
     'src/*.mjs',
     'src/**/*.js',
     'src/**/*.mjs',
+    'src/**/*.vue',
   ).filter(
     (file) =>
       !file.startsWith('src/i18n/') &&