fix(i18n): address the ru review — units, Cyrillic regexes, locale registry

Dose bank
- DRUG_UNIT learns мг / мкг / мл / ЕД / МЕ, so "2,4 мг" anchors a dose again.
- The bank matches verb-first Russian word order too ("принимайте 2 таблетки",
  "пропустите дозу метформина", "начните с 5 мг"), and the Cyrillic drug names
  people actually see on the box; the deferral words ("спросите врача",
  "как назначено") stand those shapes down.

Cyrillic-safe regexes
- \w and \b are ASCII in JavaScript: every stem in the ru bank and in
  population-norms/ru.ts is [а-яё]*, and the word edges are lookarounds
  (?<![а-яёa-z]), so «высокий риск» and «нормальный диапазон» match again.
- coach-prose-grounding: Russian month names in the genitive, a space as the
  thousands separator in parseLocaleNumber and numFrag, and Cyrillic-safe
  edges around the written-date pattern.

Registered everywhere a locale has to be
- targetLanguageName() returns "Russian", so the coach, the period narrative
  and the document descriptions stop saying "write in English".
- i18n-key-tool.mjs, split-description.mjs, LOINC name normalisation (it
  stripped Cyrillic, so no Russian lab name resolved), HOST_TLDS (ru/by/kz/ua),
  no-key-fallbacks (32 tables), country-label, the AUDIT-C standard drink.
- docs/api/openapi.yaml regenerated.

Questionnaires
- The PHQ-9 / GAD-7 source comments no longer claim no validated Russian
  version exists (Zolotareva 2023; Pfizer's official screeners).
- WHO-5 items are gender-neutral: «чувствовал(а)».
- "body fat" and "fat mass" both read «Жировая масса»; body fat is now
  «Процент жировой массы», which is what the two metrics measure.

Tests
- ru in the 13 locale tables, plus mood, onboarding, instruments, clinician
  view, status summary, describe screen, citation coverage and LOINC.
- i18n-no-dot-separator: the ru bundle is exempt from the dash rule (a spaced
  dash is Russian punctuation, not a fragment join); the middle dot still
  fails there.
- Two 800-line baselines raised by the 12 and 5 lines this change adds.

pnpm typecheck, pnpm openapi:check and the full suite (36 316 tests) pass.

src/__tests__/baselines/source-file-lines.json

@@ -1,7 +1,7 @@
 {
   "$comment": "Production files over 800 lines and their length. Maintained by src/__tests__/source-size-ratchet.test.ts.",
   "count": 84,
-  "total": 94362,
+  "total": 94379,
   "entries": {
     "app/medications/page-client.tsx": 839,
     "components/charts/mood-chart.tsx": 1166,
@@ -22,14 +22,14 @@
     "components/timeline/timeline-geometry.ts": 1288,
     "lib/ai/anthropic-client.ts": 804,
     "lib/ai/coach/about-me.ts": 1012,
-    "lib/ai/coach/coach-prose-grounding.ts": 1079,
+    "lib/ai/coach/coach-prose-grounding.ts": 1091,
     "lib/ai/coach/persistence.ts": 1218,
     "lib/ai/coach/results/metric-table-tool.ts": 1102,
     "lib/ai/coach/snapshot.ts": 1346,
     "lib/ai/coach/stream-events.ts": 817,
     "lib/ai/coach/types.ts": 1011,
     "lib/ai/codex-client.ts": 907,
-    "lib/ai/prompts/insight-generator.ts": 1110,
+    "lib/ai/prompts/insight-generator.ts": 1115,
     "lib/ai/provider.ts": 1628,
     "lib/analytics/score/reader.ts": 998,
     "lib/analytics/sleep-night.ts": 1345,

src/__tests__/baselines/source-function-lines.json

@@ -1,7 +1,7 @@
 {
   "$comment": "Production functions over 200 lines, keyed \"file :: name\", and their length. Maintained by src/__tests__/source-size-ratchet.test.ts.",
   "count": 345,
-  "total": 111929,
+  "total": 111928,
   "entries": {
     "app/achievements/page.tsx :: AchievementsPage": 206,
     "app/api/admin/backups/upload/route.ts :: apiHandler(arg)": 275,
@@ -45,7 +45,7 @@
     "app/coach/plans/page.tsx :: CoachPlansBody": 216,
     "app/insights/catalog/page.tsx :: MetricCatalogPage": 204,
     "app/insights/medications/page.tsx :: InsightsMedikamentePage": 265,
-    "app/insights/page-client.tsx :: InsightsPageClient": 376,
+    "app/insights/page-client.tsx :: InsightsPageClient": 375,
     "app/labs/page.tsx :: LabsPage": 228,
     "app/medications/page-client.tsx :: MedicationsPageClient": 590,
     "app/notifications/page.tsx :: NotificationsPage": 327,