The first PR caught all `var(--color-bg-muted, #fallback)` sites. This catches
the 5 remaining `var(--color-bg-muted)` sites *without* fallback in the admin
email templates page (.admin-et-card-key, .admin-et-card-lang-btn:hover,
.admin-et-variable-type, .admin-et-preview-subject, .admin-et-version-row:hover).
Without fallback, an undefined custom property resolves to `unset` →
`transparent`, so these elements rendered with no visible background in
either mode (rather than light-grey in light mode like the fallback-form
variant). Same root cause though: the `--color-bg-muted` token name was
never defined anywhere.
All 10 sites (5 with hex fallback + 5 without) now use `--color-surface-muted`.
Build clean.