i18n: Sprache oben, data-i18n ergänzt, localStorage-Persistenz

- Sprachdropdown an den Anfang des Einstellungs-Panels verschoben
- data-i18n für Settings-Header, Speichern-Button und Nav-Tabs ergänzt,
  damit diese beim Sprachwechsel sofort übersetzt werden
- setLang() speichert gewählte Sprache in localStorage (bleibt über
  Seitenreloads hinweg erhalten); currentLang wird beim Modulstart aus
  localStorage initialisiert
- getLang() in openSettingsModal statt state.settings.language, damit
  das Dropdown immer die aktive Sprache zeigt

frontend/index.html

@@ -385,14 +385,14 @@
       <button class="icon-btn modal-close" data-modal="modal-settings" style="margin-right:8px">
         <svg viewBox="0 0 24 24" fill="currentColor" width="20" height="20"><path d="M20 11H7.83l5.59-5.59L12 4l-8 8 8 8 1.41-1.41L7.83 13H20v-2z"/></svg>
       </button>
-      <h3>Einstellungen</h3>
-      <button class="btn btn-primary" id="settings-save" style="margin-left:auto">Speichern</button>
+      <h3 data-i18n="settings_title">Einstellungen</h3>
+      <button class="btn btn-primary" id="settings-save" style="margin-left:auto" data-i18n="save">Speichern</button>
     </div>
     <div class="settings-page-body">
       <nav class="settings-nav">
-        <button class="settings-nav-btn active" data-panel="general">Darstellung</button>
-        <button class="settings-nav-btn" data-panel="google">Google Konten</button>
-        <button class="settings-nav-btn hidden" data-panel="users" id="settings-nav-users">Benutzerverwaltung</button>
+        <button class="settings-nav-btn active" data-panel="general" data-i18n="settings_nav_appearance">Darstellung</button>
+        <button class="settings-nav-btn" data-panel="google" data-i18n="settings_nav_google">Google Konten</button>
+        <button class="settings-nav-btn hidden" data-panel="users" id="settings-nav-users" data-i18n="settings_nav_users">Benutzerverwaltung</button>
       </nav>
 
       <div class="settings-panels">
@@ -400,7 +400,15 @@
         <!-- Einstellungen (merged: Darstellung + Ansicht & Raster + Ausgeblendete Kalender) -->
         <div class="settings-panel active" id="settings-panel-general">
 
-          <h4 class="panel-title" data-i18n="settings_colors">Farben</h4>
+          <h4 class="panel-title" data-i18n="settings_language">Sprache</h4>
+          <div class="form-group">
+            <select id="cfg-language">
+              <option value="de">Deutsch</option>
+              <option value="en">English</option>
+            </select>
+          </div>
+
+          <h4 class="panel-title" style="margin-top:24px" data-i18n="settings_colors">Farben</h4>
           <div class="form-group">
             <label data-i18n="settings_primary_color">Primärfarbe</label>
             <div class="ev-color-row">
@@ -474,14 +482,6 @@
             <button class="contrast-btn" data-val="100"><span class="hour-preview">━━━━━</span><span class="contrast-lbl" data-i18n="hour_large">Gross</span></button>
           </div>
 
-          <h4 class="panel-title" style="margin-top:24px" data-i18n="settings_language">Sprache</h4>
-          <div class="form-group">
-            <select id="cfg-language">
-              <option value="de">Deutsch</option>
-              <option value="en">English</option>
-            </select>
-          </div>
-
           <h4 class="panel-title" style="margin-top:24px" data-i18n="settings_hidden_cals">Ausgeblendete Kalender</h4>
           <div id="hidden-cals-list"><span style="font-size:13px;color:var(--text-3)" data-i18n="settings_no_hidden_cals">Keine ausgeblendeten Kalender</span></div>
         </div>

frontend/js/calendar.js

@@ -4,7 +4,7 @@ import { renderMonth }  from './views/month.js';
 import { renderWeek }   from './views/week.js';
 import { renderAgenda } from './views/agenda.js';
 import { openColorPicker } from './color-picker.js';
-import { t, setLang, applyLang } from './i18n.js';
+import { t, setLang, getLang } from './i18n.js';
 
 // Fetch avatar image as blob URL (with auth header)
 function fetchAvatarBlob() {
@@ -1046,7 +1046,7 @@ function openSettingsModal() {
     document.getElementById(id + '-preview').style.background = val;
   });
   document.getElementById('cfg-dim-past').checked = !!s.dim_past_events;
-  document.getElementById('cfg-language').value = s.language || 'de';
+  document.getElementById('cfg-language').value = getLang();
 
   // Set active contrast/hour-height buttons
   [

frontend/js/i18n.js

@@ -364,13 +364,16 @@ const translations = {
   },
 };
 
-let currentLang = 'de';
+let currentLang = (() => {
+  try { const l = localStorage.getItem('lang'); return (l && translations[l]) ? l : 'de'; } catch (_) { return 'de'; }
+})();
 
 export function getLang() { return currentLang; }
 
 export function setLang(lang) {
   currentLang = (lang && translations[lang]) ? lang : 'de';
   document.documentElement.lang = currentLang;
+  try { localStorage.setItem('lang', currentLang); } catch (_) {}
   applyLang();
 }