Fix: localize reply/forward quote header incl. sender address

The reply/forward quote header was always emitted in English ("On {date},
{from} wrote:", "---------- Forwarded message ----------", From/Date/Subject)
regardless of UI language, in both the main path (lib/quote-header.ts) and the
composer's inline fallback. quote-header.ts now takes an optional localized
QuoteHeaderLabels set (English defaults preserved for back-compat); page.tsx
builds it from a new quote_header message namespace, and the composer fallback
uses the same keys. Added the quote_header namespace to all 17 locales.

Also folds in the forward-sender-address fix: the forward "From:" line now
shows the full "Name <email>" like every mail client (the reply line keeps the
bare name, which reads naturally in "On … wrote:").

app/(main)/[locale]/page.tsx

@@ -81,6 +81,7 @@ const SCHEDULED_MAILBOX_ID = '__scheduled__';
 export default function Home() {
   const t = useTranslations();
   const tCommon = useTranslations('common');
+  const tQuote = useTranslations('quote_header');
   const { appName } = useConfig();
   const mailLayout = useSettingsStore((state) => state.mailLayout);
   const [showComposer, setShowComposer] = useState(false);
@@ -1212,13 +1213,20 @@ export default function Home() {
         locale: useLocaleStore.getState().locale,
         timeFormat: useSettingsStore.getState().timeFormat,
         unknownLabel: tCommon('unknown'),
+        labels: {
+          formatReplyLine: (vars) => tQuote('reply_line', vars),
+          forwardedSeparator: tQuote('forwarded_separator'),
+          fromLabel: tQuote('from_label'),
+          dateLabel: tQuote('date_label'),
+          subjectLabel: tQuote('subject_label'),
+        },
       });
       setComposerQuoteHeader(header);
     } catch (err) {
       console.warn('[quote-header] plugin transform failed; using default', err);
       setComposerQuoteHeader(null);
     }
-  }, [tCommon]);
+  }, [tCommon, tQuote]);
 
   // Force a clean composer remount on every fresh entry point so prior
   // compose state can't bleed into the new session (#329 C). The composer is