On a fresh CF deployment, if the first request hits a public page, the
middleware fast-path skips runtime init. Template helpers like
getSiteSettings() then query an empty database and crash with
'no such table: options'.
Add a one-time setup probe in the middleware fast-path: check if the
migrations table exists, and redirect to the setup wizard if not.
The check is cached for the worker lifetime after first success.
Also includes release workflow update to use GitHub App token and
admin branding changeset.
