feat(admin): echtes Super-Admin-Benutzer-Management + letzte Anmeldung

- Super-Admin sieht jetzt ALLE Benutzer über alle Mandanten in einer Tabelle
  (statt nur Server-Admins). Neue Spalten: Mandant, Letzte Anmeldung, Status
- Einzelne Benutzer sperren/entsperren: User.isActive (Schema + Auto-Migration),
  Login-Sperre für deaktivierte Konten, PATCH /api/admin/users/[id] { isActive }
- GET /api/admin/users liefert jetzt lastLoginAt + isActive
- Selbstsperre verhindert; admin@lageplan.local geschützt
- Version 1.4.6

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/app/admin/page.tsx

@@ -56,6 +56,7 @@ import {
   Building2,
 } from 'lucide-react'
 import Link from 'next/link'
+import { formatDateTime } from '@/lib/utils'
 import { TenantDetailDialog } from '@/components/admin/tenant-detail-dialog'
 import { HoseSettingsDialog } from '@/components/dialogs/hose-settings-dialog'
 import { SettingsTab } from '@/components/admin/settings-tab'
@@ -92,6 +93,8 @@ interface UserRecord {
   name: string
   role: 'SERVER_ADMIN' | 'TENANT_ADMIN' | 'OPERATOR' | 'VIEWER'
   emailVerified?: boolean
+  isActive?: boolean
+  lastLoginAt?: string | null
   createdAt: string
   updatedAt: string
   memberships?: { tenant: { id: string; name: string; slug: string } }[]
@@ -454,6 +457,25 @@ export default function AdminPage() {
     } catch { toast({ title: 'Fehler', variant: 'destructive' }) }
   }
 
+  const handleToggleUserActive = async (targetUser: UserRecord) => {
+    const willDeactivate = targetUser.isActive !== false
+    if (willDeactivate && !confirm(`"${targetUser.name}" sperren? Der Benutzer kann sich dann nicht mehr anmelden.`)) return
+    try {
+      const res = await fetch(`/api/admin/users/${targetUser.id}`, {
+        method: 'PATCH',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ isActive: !willDeactivate }),
+      })
+      if (res.ok) {
+        toast({ title: willDeactivate ? 'Benutzer gesperrt' : 'Benutzer entsperrt' })
+        fetchData()
+      } else {
+        const err = await res.json()
+        toast({ title: 'Fehler', description: err.error, variant: 'destructive' })
+      }
+    } catch { toast({ title: 'Fehler', variant: 'destructive' }) }
+  }
+
   const handleResetUserPassword = async (targetUser: UserRecord) => {
     try {
       const res = await fetch(`/api/admin/users/${targetUser.id}/reset-password`, { method: 'POST' })
@@ -564,7 +586,7 @@ export default function AdminPage() {
               </TabsTrigger>
               <TabsTrigger value="users" className="gap-2">
                 <Users className="w-4 h-4" />
-                Server Admins
+                Benutzer
               </TabsTrigger>
               <TabsTrigger value="settings" className="gap-2">
                 <Settings className="w-4 h-4" />
@@ -716,10 +738,9 @@ export default function AdminPage() {
           <TabsContent value="users" className="space-y-4">
             <div className="flex justify-between items-center">
               <p className="text-sm text-muted-foreground">
-                {user?.role === 'SERVER_ADMIN'
-                  ? `${users.filter(u => u.role === 'SERVER_ADMIN').length} Server-Admin(s)`
-                  : `${users.length} Benutzer`
-                }
+                {users.length} Benutzer
+                {users.filter(u => u.isActive === false).length > 0 &&
+                  ` · ${users.filter(u => u.isActive === false).length} gesperrt`}
               </p>
               <Button onClick={() => {
                 setEditingUser(null); setUserName(''); setUserEmail(''); setUserPassword(''); setUserPasswordConfirm(''); setUserRole('OPERATOR'); setIsUserDialogOpen(true)
@@ -728,20 +749,25 @@ export default function AdminPage() {
                 Neuer Benutzer
               </Button>
             </div>
-            <div className="border rounded-lg overflow-hidden">
+            <div className="border rounded-lg overflow-x-auto">
               <table className="w-full">
                 <thead className="bg-muted/50">
                   <tr>
                     <th className="text-left text-xs font-medium text-muted-foreground px-4 py-3">Name</th>
                     <th className="text-left text-xs font-medium text-muted-foreground px-4 py-3">E-Mail</th>
                     <th className="text-left text-xs font-medium text-muted-foreground px-4 py-3">Rolle</th>
-                    <th className="text-left text-xs font-medium text-muted-foreground px-4 py-3">Projekte</th>
+                    <th className="text-left text-xs font-medium text-muted-foreground px-4 py-3">Mandant</th>
+                    <th className="text-left text-xs font-medium text-muted-foreground px-4 py-3">Letzte Anmeldung</th>
+                    <th className="text-left text-xs font-medium text-muted-foreground px-4 py-3">Status</th>
                     <th className="text-right text-xs font-medium text-muted-foreground px-4 py-3">Aktionen</th>
                   </tr>
                 </thead>
                 <tbody className="divide-y">
-                  {(user?.role === 'SERVER_ADMIN' ? users.filter(u => u.role === 'SERVER_ADMIN') : users).map(u => (
-                    <tr key={u.id} className="hover:bg-muted/30 transition-colors">
+                  {users.map(u => {
+                    const inactive = u.isActive === false
+                    const tenantNames = (u.memberships || []).map(m => m.tenant?.name).filter(Boolean)
+                    return (
+                    <tr key={u.id} className={`hover:bg-muted/30 transition-colors ${inactive ? 'opacity-50' : ''}`}>
                       <td className="px-4 py-3">
                         <div className="flex items-center gap-2">
                           <div className={`w-8 h-8 rounded-full flex items-center justify-center text-xs font-bold text-white ${
@@ -752,14 +778,7 @@ export default function AdminPage() {
                           <span className="font-medium text-sm">{u.name}</span>
                         </div>
                       </td>
-                      <td className="px-4 py-3 text-sm text-muted-foreground">
-                        <div className="flex items-center gap-1.5">
-                          {u.email}
-                          {u.emailVerified === false && (
-                            <span className="text-[10px] px-1.5 py-0.5 rounded bg-amber-100 text-amber-700 font-medium">unverifiziert</span>
-                          )}
-                        </div>
-                      </td>
+                      <td className="px-4 py-3 text-sm text-muted-foreground">{u.email}</td>
                       <td className="px-4 py-3">
                         <span className={`text-xs px-2 py-1 rounded-full font-medium ${
                           u.role === 'SERVER_ADMIN' ? 'bg-red-100 text-red-700' :
@@ -770,7 +789,25 @@ export default function AdminPage() {
                           {ROLES.find(r => r.value === u.role)?.label || u.role}
                         </span>
                       </td>
-                      <td className="px-4 py-3 text-sm text-muted-foreground">{u._count?.projects || 0}</td>
+                      <td className="px-4 py-3 text-sm text-muted-foreground">
+                        {tenantNames.length > 0 ? tenantNames.join(', ') : <span className="text-muted-foreground/50">—</span>}
+                      </td>
+                      <td className="px-4 py-3 text-sm">
+                        {u.lastLoginAt ? (
+                          <span className="text-foreground/80">{formatDateTime(u.lastLoginAt)}</span>
+                        ) : (
+                          <span className="text-amber-600 text-xs">Nie eingeloggt</span>
+                        )}
+                      </td>
+                      <td className="px-4 py-3">
+                        {inactive ? (
+                          <span className="text-xs px-2 py-1 rounded-full font-medium bg-red-100 text-red-700">Gesperrt</span>
+                        ) : u.emailVerified === false ? (
+                          <span className="text-xs px-2 py-1 rounded-full font-medium bg-amber-100 text-amber-700">Unverifiziert</span>
+                        ) : (
+                          <span className="text-xs px-2 py-1 rounded-full font-medium bg-green-100 text-green-700">Aktiv</span>
+                        )}
+                      </td>
                       <td className="px-4 py-3 text-right">
                         <div className="flex justify-end gap-1">
                           {u.emailVerified === false && (
@@ -783,19 +820,25 @@ export default function AdminPage() {
                             onClick={() => handleResetUserPassword(u)}>
                             <KeyRound className="w-4 h-4" />
                           </Button>
-                          <Button variant="ghost" size="icon" className="h-8 w-8" onClick={() => {
+                          <Button variant="ghost" size="icon" className="h-8 w-8" title="Bearbeiten" onClick={() => {
                             setEditingUser(u); setUserName(u.name); setUserEmail(u.email); setUserPassword(''); setUserPasswordConfirm(''); setUserRole(u.role); setIsUserDialogOpen(true)
                           }}>
                             <Pencil className="w-4 h-4" />
                           </Button>
-                          <Button variant="ghost" size="icon" className="h-8 w-8 text-destructive" onClick={() => handleDeleteUser(u.id)}
+                          <Button variant="ghost" size="icon" className={`h-8 w-8 ${inactive ? 'text-green-600' : 'text-amber-600'}`}
+                            title={inactive ? 'Entsperren' : 'Sperren'}
+                            onClick={() => handleToggleUserActive(u)}
+                            disabled={u.id === user?.id || u.email === 'admin@lageplan.local'}>
+                            {inactive ? <CheckCircle className="w-4 h-4" /> : <Ban className="w-4 h-4" />}
+                          </Button>
+                          <Button variant="ghost" size="icon" className="h-8 w-8 text-destructive" title="Löschen" onClick={() => handleDeleteUser(u.id)}
                             disabled={u.email === 'admin@lageplan.local'}>
                             <Trash2 className="w-4 h-4" />
                           </Button>
                         </div>
                       </td>
                     </tr>
-                  ))}
+                  )})}
                 </tbody>
               </table>
             </div>

src/app/api/admin/users/[id]/route.ts

@@ -9,6 +9,7 @@ const updateUserSchema = z.object({
   password: z.string().min(6).optional(),
   role: z.enum(['SERVER_ADMIN', 'TENANT_ADMIN', 'OPERATOR', 'VIEWER']).optional(),
   emailVerified: z.boolean().optional(),
+  isActive: z.boolean().optional(),
 })
 
 export async function PATCH(
@@ -46,6 +47,13 @@ export async function PATCH(
     if (data.role) updateData.role = data.role
     if (data.password) updateData.password = await hashPassword(data.password)
     if (data.emailVerified !== undefined) updateData.emailVerified = data.emailVerified
+    if (data.isActive !== undefined) {
+      // Niemand darf sich selbst sperren
+      if (data.isActive === false && session.id === params.id) {
+        return NextResponse.json({ error: 'Eigenen Account kann man nicht sperren' }, { status: 400 })
+      }
+      updateData.isActive = data.isActive
+    }
 
     const user = await (prisma as any).user.update({
       where: { id: params.id },
@@ -56,6 +64,8 @@ export async function PATCH(
         name: true,
         role: true,
         emailVerified: true,
+        isActive: true,
+        lastLoginAt: true,
         createdAt: true,
         updatedAt: true,
       },

src/app/api/admin/users/route.ts

@@ -31,6 +31,8 @@ export async function GET() {
         name: true,
         role: true,
         emailVerified: true,
+        isActive: true,
+        lastLoginAt: true,
         createdAt: true,
         updatedAt: true,
         memberships: {

src/lib/auth.ts

@@ -59,6 +59,7 @@ export async function login(
       password: true,
       role: true,
       emailVerified: true,
+      isActive: true,
     },
   }) as any)
 
@@ -71,6 +72,12 @@ export async function login(
     return { success: false, error: 'E-Mail oder Passwort falsch' }
   }
 
+  // Gesperrte Benutzer dürfen sich nicht anmelden (isActive === false).
+  // Tolerant: nur blockieren, wenn explizit false (alte Datensätze ohne Wert bleiben aktiv).
+  if (user.isActive === false) {
+    return { success: false, error: 'Ihr Konto wurde deaktiviert. Bitte kontaktieren Sie den Administrator.' }
+  }
+
   // Track email verification status (allow login regardless)
   const emailVerified = (user as any).emailVerified !== false