Fix shell details: distro name, storage path only in footer

- OS name comes from /etc/os-release (e.g. 'CachyOS Linux'), mirroring
  the original app's os_utils; macOS/Windows get proper names too
- Status pill shows the name as-is instead of uppercasing it
- Removed the watched-folder path next to the logo; it now appears only
  in the footer strip (spec updated to match)

frontend/src/components/AppShell.tsx

@@ -53,15 +53,6 @@ export function AppShell() {
             </span>
           </Link>
 
-          {status ? (
-            <span
-              className="hidden max-w-[240px] truncate font-mono text-[11px] text-ctp-overlay0 md:block"
-              title={status.watched_folder}
-            >
-              {status.watched_folder}
-            </span>
-          ) : null}
-
           {showSidebarToggle ? (
             <button
               type="button"