refactor(admin): split email-templates page.tsx into colocated components

Extract tabs nav, templates grid, editor split view, settings form,
logs table, and data-loading/actions hook into _components/ and
_hooks/. page.tsx reduced from 816 to 88 LOC.

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

admin-compliance/app/sdk/email-templates/_components/TabNav.tsx

@@ -0,0 +1,43 @@
+'use client'
+
+import { TabId } from '../_types'
+
+interface TabNavProps {
+  activeTab: TabId
+  onTabChange: (tab: TabId) => void
+  logsTotal: number
+}
+
+const TABS: { id: TabId; label: string }[] = [
+  { id: 'templates', label: 'Templates' },
+  { id: 'editor', label: 'Editor' },
+  { id: 'settings', label: 'Einstellungen' },
+  { id: 'logs', label: 'Logs' },
+]
+
+export function TabNav({ activeTab, onTabChange, logsTotal }: TabNavProps) {
+  return (
+    <div className="border-b border-gray-200">
+      <nav className="flex gap-1 -mb-px">
+        {TABS.map(tab => (
+          <button
+            key={tab.id}
+            onClick={() => onTabChange(tab.id)}
+            className={`px-4 py-3 text-sm font-medium border-b-2 transition-colors ${
+              activeTab === tab.id
+                ? 'border-purple-600 text-purple-600'
+                : 'border-transparent text-gray-500 hover:text-gray-700 hover:border-gray-300'
+            }`}
+          >
+            {tab.label}
+            {tab.id === 'logs' && logsTotal > 0 && (
+              <span className="ml-1.5 px-1.5 py-0.5 text-xs rounded-full bg-gray-100 text-gray-600">
+                {logsTotal}
+              </span>
+            )}
+          </button>
+        ))}
+      </nav>
+    </div>
+  )
+}