v1.11.2 — admin auto sign-out on expired token

Admin auth fix.

Fix

• A GitHub 401 ("Bad credentials") — an expired OAuth-worker session or a revoked/mistyped token — now signs the writer out automatically and returns them to the sign-in screen, instead of dead-ending an action (e.g. Save) on an error toast. The central gh() call clears the dead token on any 401 and app.js routes to sign-in, so every GitHub call is covered.

Only admin/js/{github,app}.js changed.