[split-required] Split website + studio-v2 monoliths (Phase 3 continued)

Website (14 monoliths split):
- compliance/page.tsx (1,519 → 9), docs/audit (1,262 → 20)
- quality (1,231 → 16), alerts (1,203 → 10), docs (1,202 → 11)
- i18n.ts (1,173 → 8 language files)
- unity-bridge (1,094 → 12), backlog (1,087 → 6)
- training (1,066 → 8), rag (1,063 → 8)
- Deleted index_original.ts (4,899 LOC dead backup)

Studio-v2 (5 monoliths split):
- meet/page.tsx (1,481 → 9), messages (1,166 → 9)
- AlertsB2BContext.tsx (1,165 → 5 modules)
- alerts-b2b/page.tsx (1,019 → 6), korrektur/archiv (1,001 → 6)

All existing imports preserved. Zero new TypeScript errors.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

studio-v2/app/messages/_components/ContextMenu.tsx

@@ -0,0 +1,47 @@
+'use client'
+
+interface ContextMenuProps {
+  isDark: boolean
+  contextMenu: { x: number; y: number; messageId: string }
+  currentConversationId: string | null
+  deleteMessage: (convId: string, msgId: string) => void
+  onClose: () => void
+}
+
+export function ContextMenu({ isDark, contextMenu, currentConversationId, deleteMessage, onClose }: ContextMenuProps) {
+  return (
+    <div
+      className={`fixed rounded-xl border shadow-xl overflow-hidden z-50 ${
+        isDark
+          ? 'bg-slate-900 border-white/20'
+          : 'bg-white border-slate-200'
+      }`}
+      style={{ top: contextMenu.y, left: contextMenu.x }}
+    >
+      <button
+        onClick={() => {
+          // Show quick reactions
+          onClose()
+        }}
+        className={`w-full px-4 py-2 text-left text-sm transition-colors ${
+          isDark ? 'hover:bg-white/10 text-white' : 'hover:bg-slate-100 text-slate-700'
+        }`}
+      >
+        Reagieren
+      </button>
+      <button
+        onClick={() => {
+          if (currentConversationId) {
+            deleteMessage(currentConversationId, contextMenu.messageId)
+          }
+          onClose()
+        }}
+        className={`w-full px-4 py-2 text-left text-sm transition-colors ${
+          isDark ? 'hover:bg-red-500/20 text-red-400' : 'hover:bg-red-50 text-red-600'
+        }`}
+      >
+        Loeschen
+      </button>
+    </div>
+  )
+}