calculateNewExpiryTime only handled s/h/d, but the grace-period
validation and backend accept m, w, and mo as well. Entering any of
those in the Expire Key field caused the function to return null,
which then propagated as expires: null in the onKeyUpdate payload —
the parent UI would then render the expiry as "Never" even though
the backend had correctly applied the new expiry.
Extend the suffix check to cover s/m/h/d/w/mo, matching "mo" before
"m" so "1mo" isn't misread as minutes. Also nullish-coalesce the
call site so an unparseable duration falls back to the previous
expiry instead of null. Add parametric tests for each supported
suffix plus a regression test for the null fallback.
1d50f774e2