refactor: Unified Inbox aus Core entfernt (nach Lehrer migriert)

- Mail-Seite, API-Route, Kommunikation-Kategorie entfernt
- Screen-Flow: Mail-Node und Kommunikation-Legende entfernt

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

admin-core/app/api/admin/mail/route.ts

@@ -1,81 +0,0 @@
-import { NextResponse } from 'next/server'
-
-/**
- * Server-side proxy for Mailpit API
- * Avoids CORS and mixed-content issues by fetching from server
- */
-
-// Use internal Docker hostname when running in container
-const getMailpitHost = (): string => {
-  return process.env.BACKEND_URL ? 'mailpit' : 'localhost'
-}
-
-export async function GET() {
-  const host = getMailpitHost()
-  const mailpitUrl = `http://${host}:8025/api/v1/info`
-
-  try {
-    const response = await fetch(mailpitUrl, {
-      method: 'GET',
-      signal: AbortSignal.timeout(5000),
-    })
-
-    if (!response.ok) {
-      return NextResponse.json(
-        { error: 'Mailpit API error', status: response.status },
-        { status: response.status }
-      )
-    }
-
-    const data = await response.json()
-
-    // Transform Mailpit response to our expected format
-    return NextResponse.json({
-      stats: {
-        totalAccounts: 1,
-        activeAccounts: 1,
-        totalEmails: data.Messages || 0,
-        unreadEmails: data.Unread || 0,
-        totalTasks: 0,
-        pendingTasks: 0,
-        overdueTasks: 0,
-        aiAnalyzedCount: 0,
-        lastSyncTime: new Date().toISOString(),
-      },
-      accounts: [{
-        id: 'mailpit-dev',
-        email: 'dev@mailpit.local',
-        displayName: 'Mailpit (Development)',
-        imapHost: 'mailpit',
-        imapPort: 1143,
-        smtpHost: 'mailpit',
-        smtpPort: 1025,
-        status: 'active' as const,
-        lastSync: new Date().toISOString(),
-        emailCount: data.Messages || 0,
-        unreadCount: data.Unread || 0,
-        createdAt: new Date().toISOString(),
-      }],
-      syncStatus: {
-        running: false,
-        accountsInProgress: [],
-        lastCompleted: new Date().toISOString(),
-        errors: [],
-      },
-      mailpitInfo: {
-        version: data.Version,
-        databaseSize: data.DatabaseSize,
-        uptime: data.RuntimeStats?.Uptime,
-      }
-    })
-  } catch (error) {
-    console.error('Failed to fetch from Mailpit:', error)
-    return NextResponse.json(
-      {
-        error: 'Failed to connect to Mailpit',
-        details: error instanceof Error ? error.message : 'Unknown error'
-      },
-      { status: 503 }
-    )
-  }
-}