PR-4 of the locale-expansion plan. 215,363 strings retranslated across the 65 catalogs with the new `sync-ui-keys --retranslate-identical`; the share of leaves still identical to English drops from a mean of 18.3 % to 1.8 % (Spanish 56 → 2.1). No `__MISSING__` marker or missing key is left; zh glossary normalised; pinned product/flag names kept English and allowlisted. Baseline tightened and the CI step `i18n real-translation ratio` is blocking from here on.
⚠️ base-red inherited: #12732
Integrated into release/v3.8.8. Applied review fixes: moved the SELECT 1 into a pingDb() db helper (no raw SQL in route, Hard Rule #5) + the 503 catch no longer leaks err.message (Hard Rule #12). Thanks @herjarsa!
