Simplify i18n: remove old react-intl artifacts, rename formatMessage to t, replace FormattedMessage with t.rich().

- Rewrite messages.ts to plain string key maps (remove MessageDescriptor)
- Rewrite useMessages hook to expose t from useTranslations() directly
- Rename formatMessage → t across 193 consumer files
- Replace custom FormattedMessage component with next-intl t.rich()
- Update 52 language files to use rich text tags (<b>, <a>)
- Remove all direct imports from @/components/messages in favor of useMessages()

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/app/(main)/settings/preferences/DateRangeSetting.tsx

@@ -6,7 +6,7 @@ import { DATE_RANGE_CONFIG, DEFAULT_DATE_RANGE_VALUE } from '@/lib/constants';
 import { getItem, setItem } from '@/lib/storage';
 
 export function DateRangeSetting() {
-  const { formatMessage, labels } = useMessages();
+  const { t, labels } = useMessages();
   const [date, setDate] = useState(getItem(DATE_RANGE_CONFIG) || DEFAULT_DATE_RANGE_VALUE);
 
   const handleChange = (value: string) => {
@@ -27,7 +27,7 @@ export function DateRangeSetting() {
         placement="bottom start"
         style={{ minWidth: '250px' }}
       />
-      <Button onPress={handleReset}>{formatMessage(labels.reset)}</Button>
+      <Button onPress={handleReset}>{t(labels.reset)}</Button>
     </Row>
   );
 }

src/app/(main)/settings/preferences/LanguageSetting.tsx

@@ -6,7 +6,7 @@ import { languages } from '@/lib/lang';
 
 export function LanguageSetting() {
   const [search, setSearch] = useState('');
-  const { formatMessage, labels } = useMessages();
+  const { t, labels } = useMessages();
   const { locale, saveLocale } = useLocale();
   const items = search
     ? Object.keys(languages).filter(n => {
@@ -43,7 +43,7 @@ export function LanguageSetting() {
         ))}
         {!items.length && <ListItem></ListItem>}
       </Select>
-      <Button onPress={handleReset}>{formatMessage(labels.reset)}</Button>
+      <Button onPress={handleReset}>{t(labels.reset)}</Button>
     </Row>
   );
 }

src/app/(main)/settings/preferences/PreferenceSettings.tsx

@@ -8,7 +8,7 @@ import { VersionSetting } from './VersionSetting';
 
 export function PreferenceSettings() {
   const { user } = useLoginQuery();
-  const { formatMessage, labels } = useMessages();
+  const { t, labels } = useMessages();
 
   if (!user) {
     return null;
@@ -17,23 +17,23 @@ export function PreferenceSettings() {
   return (
     <Column gap="6">
       <Column>
-        <Label>{formatMessage(labels.defaultDateRange)}</Label>
+        <Label>{t(labels.defaultDateRange)}</Label>
         <DateRangeSetting />
       </Column>
       <Column>
-        <Label>{formatMessage(labels.timezone)}</Label>
+        <Label>{t(labels.timezone)}</Label>
         <TimezoneSetting />
       </Column>
       <Column>
-        <Label>{formatMessage(labels.language)}</Label>
+        <Label>{t(labels.language)}</Label>
         <LanguageSetting />
       </Column>
       <Column>
-        <Label>{formatMessage(labels.theme)}</Label>
+        <Label>{t(labels.theme)}</Label>
         <ThemeSetting />
       </Column>
       <Column>
-        <Label>{formatMessage(labels.version)}</Label>
+        <Label>{t(labels.version)}</Label>
         <VersionSetting />
       </Column>
     </Column>

src/app/(main)/settings/preferences/PreferencesPage.tsx

@@ -7,12 +7,12 @@ import { useMessages } from '@/components/hooks';
 import { PreferenceSettings } from './PreferenceSettings';
 
 export function PreferencesPage() {
-  const { formatMessage, labels } = useMessages();
+  const { t, labels } = useMessages();
 
   return (
     <PageBody>
       <Column gap="6">
-        <PageHeader title={formatMessage(labels.preferences)} />
+        <PageHeader title={t(labels.preferences)} />
         <Panel>
           <PreferenceSettings />
         </Panel>

src/app/(main)/settings/preferences/TimezoneSetting.tsx

@@ -7,7 +7,7 @@ const timezones = Intl.supportedValuesOf('timeZone');
 
 export function TimezoneSetting() {
   const [search, setSearch] = useState('');
-  const { formatMessage, labels } = useMessages();
+  const { t, labels } = useMessages();
   const { timezone, saveTimezone } = useTimezone();
   const items = search
     ? timezones.filter(n => n.toLowerCase().includes(search.toLowerCase()))
@@ -39,7 +39,7 @@ export function TimezoneSetting() {
         ))}
         {!items.length && <ListItem></ListItem>}
       </Select>
-      <Button onPress={handleReset}>{formatMessage(labels.reset)}</Button>
+      <Button onPress={handleReset}>{t(labels.reset)}</Button>
     </Row>
   );
 }