feat(i18n): register Brazilian Portuguese as a locale

Add pt-BR to the locale list and everything that hangs off it: the
client loader, Intl and date-fns mapping, the reply-language footers of
the Coach and insights prompts (English body, pt-BR footer, the same
path Korean and Dutch take), the citation-coverage normative words, the
no-key fallback copy, the AUDIT-C standard-drink line, country labels,
period search, CSV yes/no cells and the Telegram bare-word aliases.

The locale enums in the extract, managed-profile and record-settings
schemas now derive from the locale list instead of repeating it, and
the five notification and login-alert routes share one isLocale guard
instead of hand-rolled chains, so a later locale is one edit there.
A language tag is matched exactly and case-insensitively before its
primary subtag, so pt-BR and pt-PT browsers land on the Portuguese
bundle rather than English, and AUDIT-C no longer cuts a region tag to
two letters.

PHQ-9, GAD-7 and WHO-5 are not marked validated for pt-BR: the wording
has not been read against the published Brazilian forms, so readers get
the English items plus the existing note.

src/components/settings/integrations/__tests__/apple-health-card.test.tsx

@@ -215,7 +215,7 @@ describe("<AppleHealthCard>", () => {
     }
   });
 
-  it.each(["en", "de", "es", "fr", "it", "pl", "ko", "nl"] as const)(
+  it.each(["en", "de", "es", "fr", "it", "pl", "ko", "nl", "pt-BR"] as const)(
     "renders localized Apple Health copy for %s without leaking keys",
     (locale) => {
       statusPayload = { lastSyncedAt: null, health: null };

src/components/settings/integrations/__tests__/integration-health-copy.test.ts

@@ -15,6 +15,7 @@ import itMessages from "../../../../../messages/it.json";
 import ko from "../../../../../messages/ko.json";
 import nl from "../../../../../messages/nl.json";
 import pl from "../../../../../messages/pl.json";
+import ptBR from "../../../../../messages/pt-BR.json";
 
 import {
   diagnosticsText,
@@ -34,6 +35,7 @@ const CATALOGS: Record<Locale, unknown> = {
   pl,
   nl,
   ko,
+  "pt-BR": ptBR,
 };
 
 function translator(locale: Locale) {