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.

scripts/i18n-key-tool.mjs

@@ -11,7 +11,7 @@
  */
 import { readFileSync, writeFileSync } from "node:fs";
 
-const LOCALES = ["de", "en", "es", "fr", "it", "pl", "ko", "nl", "pt-BR"];
+const LOCALES = ["de", "en", "es", "fr", "it", "pl", "ko", "nl", "pt-BR", "ru"];
 const file = (loc) => `messages/${loc}.json`;
 
 function read(loc) {

scripts/split-description.mjs

@@ -18,7 +18,7 @@
  */
 import { readFileSync, writeFileSync } from "node:fs";
 
-const LOCALES = ["de", "en", "es", "fr", "it", "pl", "ko", "nl", "pt-BR"];
+const LOCALES = ["de", "en", "es", "fr", "it", "pl", "ko", "nl", "pt-BR", "ru"];
 const BOUNDARY = /(?<=[.!?])\s+(?=[A-ZÄÖÜÀÂÉÈÊÎÔÙÛÇŁŚŹŻĄĆĘŃÓ0-9„"„«])/u;
 
 /**