fix: the empty document's placeholder follows the UI language

The body said "Start typing…" in every language while the header and
footer zones were localized; switching the language now redraws it.

src/lib/components/Editor.svelte

@@ -1134,6 +1134,13 @@ import { EMPTY_PAGE_DECOR, type PageDecor } from '../storage/pageDecor';
     waitForSettled();
   });
 
+  // The placeholder is a decoration, redrawn only by a view update; the UI language
+  // switching is not one, so give it a push.
+  $effect(() => {
+    t();
+    editor?.view.updateState(editor.view.state);
+  });
+
   onMount(async () => {
     // Start with empty history lists — loaded content is not an undoable edit.
     resetHistoryLog();

src/lib/editor/extensions.ts

@@ -24,6 +24,7 @@ import { Table, TableHeader, TableCell } from '@tiptap/extension-table';
 import { ResizableTableRow } from './extensions/tableRow';
 import History from '@tiptap/extension-history';
 import Placeholder from '@tiptap/extension-placeholder';
+import { t } from '../i18n/i18n.svelte';
 
 import { PageBreaks } from './extensions/pageBreaks';
 import { LineHeight } from './extensions/lineHeight';
@@ -224,7 +225,7 @@ export const extensions = [
   // and the user can keep writing below a table at the document's end.
   TrailingNode,
   History,
-  Placeholder.configure({ placeholder: 'Start typing…' }),
+  Placeholder.configure({ placeholder: () => t().app.startTyping }),
   // No defaultAlignment: it would put textAlign:'left' on every block, and that inline
   // style beats the paragraph style's alignment. Unset = follow the style; an explicit
   // 'left' stays direct formatting that overrides it, as in Word/LibreOffice.

src/lib/i18n/locales/de.ts

@@ -1035,6 +1035,7 @@ const de: Messages = {
   app: {
     documentName: 'Dokumentname',
     untitled: 'Unbenanntes Dokument',
+    startTyping: 'Hier tippen…',
     newDocument: 'Neues Dokument',
     open: 'Öffnen…',
     save: '.odt speichern',

src/lib/i18n/locales/en.ts

@@ -1041,6 +1041,7 @@ const en = {
   app: {
     documentName: 'Document name',
     untitled: 'Untitled document',
+    startTyping: 'Start typing…',
     newDocument: 'New document',
     open: 'Open…',
     save: 'Save .odt',