fix: Restore all files lost during destructive rebase

A previous `git pull --rebase origin main` dropped 177 local commits,
losing 3400+ files across admin-v2, backend, studio-v2, website,
klausur-service, and many other services. The partial restore attempt
(660295e2) only recovered some files.

This commit restores all missing files from pre-rebase ref 98933f5e
while preserving post-rebase additions (night-scheduler, night-mode UI,
NightModeWidget dashboard integration).

Restored features include:
- AI Module Sidebar (FAB), OCR Labeling, OCR Compare
- GPU Dashboard, RAG Pipeline, Magic Help
- Klausur-Korrektur (8 files), Abitur-Archiv (5+ files)
- Companion, Zeugnisse-Crawler, Screen Flow
- Full backend, studio-v2, website, klausur-service
- All compliance SDKs, agent-core, voice-service
- CI/CD configs, documentation, scripts

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

website/components/LanguageSelector.tsx

@@ -0,0 +1,89 @@
+'use client'
+
+import { useState, useRef, useEffect } from 'react'
+import { Language, LANGUAGES, isRTL } from '@/lib/i18n'
+
+interface LanguageSelectorProps {
+  currentLanguage: Language
+  onLanguageChange: (lang: Language) => void
+  compact?: boolean
+}
+
+export default function LanguageSelector({
+  currentLanguage,
+  onLanguageChange,
+  compact = false,
+}: LanguageSelectorProps) {
+  const [isOpen, setIsOpen] = useState(false)
+  const dropdownRef = useRef<HTMLDivElement>(null)
+
+  const currentLang = LANGUAGES.find((l) => l.code === currentLanguage) || LANGUAGES[0]
+
+  // Close dropdown on outside click
+  useEffect(() => {
+    function handleClickOutside(event: MouseEvent) {
+      if (dropdownRef.current && !dropdownRef.current.contains(event.target as Node)) {
+        setIsOpen(false)
+      }
+    }
+    document.addEventListener('mousedown', handleClickOutside)
+    return () => document.removeEventListener('mousedown', handleClickOutside)
+  }, [])
+
+  return (
+    <div className="relative" ref={dropdownRef}>
+      <button
+        onClick={() => setIsOpen(!isOpen)}
+        className={`flex items-center gap-2 px-3 py-2 rounded-lg border border-slate-200 hover:border-slate-300 bg-white transition-colors ${
+          compact ? 'text-sm' : ''
+        }`}
+        aria-label="Select language"
+        aria-expanded={isOpen}
+      >
+        <span className="text-lg">{currentLang.flag}</span>
+        {!compact && <span className="text-slate-700">{currentLang.name}</span>}
+        <svg
+          className={`w-4 h-4 text-slate-400 transition-transform ${isOpen ? 'rotate-180' : ''}`}
+          fill="none"
+          viewBox="0 0 24 24"
+          stroke="currentColor"
+        >
+          <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M19 9l-7 7-7-7" />
+        </svg>
+      </button>
+
+      {isOpen && (
+        <div
+          className={`absolute top-full mt-1 ${
+            isRTL(currentLanguage) ? 'left-0' : 'right-0'
+          } bg-white rounded-lg shadow-lg border border-slate-200 py-1 z-50 min-w-[160px]`}
+        >
+          {LANGUAGES.map((lang) => (
+            <button
+              key={lang.code}
+              onClick={() => {
+                onLanguageChange(lang.code)
+                setIsOpen(false)
+              }}
+              className={`w-full flex items-center gap-3 px-4 py-2 text-left hover:bg-slate-50 transition-colors ${
+                lang.code === currentLanguage ? 'bg-primary-50 text-primary-700' : 'text-slate-700'
+              }`}
+            >
+              <span className="text-lg">{lang.flag}</span>
+              <span>{lang.name}</span>
+              {lang.code === currentLanguage && (
+                <svg className="w-4 h-4 ml-auto text-primary-600" fill="currentColor" viewBox="0 0 20 20">
+                  <path
+                    fillRule="evenodd"
+                    d="M16.707 5.293a1 1 0 010 1.414l-8 8a1 1 0 01-1.414 0l-4-4a1 1 0 011.414-1.414L8 12.586l7.293-7.293a1 1 0 011.414 0z"
+                    clipRule="evenodd"
+                  />
+                </svg>
+              )}
+            </button>
+          ))}
+        </div>
+      )}
+    </div>
+  )
+}