chore: reconcile the catalogue and metric-unit guards

The widget catalogue grew to 42 ids, so the snapshot round-trip count
follows. The mood card's unit key carries "/5" rather than an empty
string — the locale-integrity guard forbids empty values, and the scale
is the honest thing to print next to a 1-to-5 score. It joins the
identical-across-locales allowlist alongside the other unit notations.

src/__tests__/i18n-english-leak-guard.test.ts

@@ -82,6 +82,7 @@ const LEGIT_IDENTICAL = new Set<string>([
   "charts.vo2Max",
   "cycle.insights.crosstab.unitGlucose",
   "dashboard.metric.unit.bmi",
+  "dashboard.metric.unit.mood",
   "dashboard.metric.unit.glucose",
   "dashboard.vo2Max",
   "dashboard.vo2MaxShort",