feat(i18n): migrate hardcoded German strings to t() across 104 components/pages — AST-based batch with re-parse gate, 423 new de.json keys; tsc clean; vitest failures byte-identical to clean-tree baseline (pre-existing)

frontend/src/pages/StartPage.tsx

@@ -64,8 +64,8 @@ export function StartPage() {
           <button
             onClick={() => navigate('/start')}
             className="p-1.5 rounded-md text-secondary-400 hover:bg-secondary-100 hover:text-secondary-700 flex items-center justify-center focus:outline-none focus-visible:ring-2 focus-visible:ring-primary-500"
-            aria-label="Zurück zur Startseite"
-            title="Zurück zur Startseite"
+            aria-label={t('startPage.zurückzurstartseite')}
+            title={t('startPage.zurückzurstartseite')}
           >
             <ArrowLeft className="w-4 h-4" />
           </button>
@@ -101,7 +101,7 @@ export function StartPage() {
         <div className="max-w-5xl mx-auto p-8">
           <div className="mb-8">
             <h1 className="text-2xl font-bold text-secondary-900">Willkommen{user?.first_name ? `, ${user.first_name}` : ''}!</h1>
-            <p className="text-sm text-secondary-500 mt-1">Wähle einen Workspace aus</p>
+            <p className="text-sm text-secondary-500 mt-1">{t('startPage.wähleeinenworkspaceaus')}</p>
           </div>
 
           {/* Dashboard stats */}
@@ -171,7 +171,7 @@ export function StartPage() {
             >
               <Plus className="w-8 h-8 text-secondary-300 group-hover:text-primary-400 transition-colors" />
               <span className="text-sm text-secondary-400 group-hover:text-primary-600 mt-2 transition-colors">
-                Workspace hinzufügen
+                {t('startPage.workspacehinzufügen')}
               </span>
             </button>
           </div>