feat: Mandanten-Zuordnung sichtbar auf Workflow-Karten + Mandanten-Filter

- Mandantenname auf allen Workflow-Karten (Grid + Liste)
- Mandantenname im Dashboard bei aktuellen Workflows
- Mandanten-Filter-Dropdown in der Workflow-Liste (für Admins/Techniker)
- Tenant-Info im Workflow-Typ ergänzt

frontend/src/pages/Dashboard.tsx

@@ -217,6 +217,10 @@ export default function Dashboard() {
                       {wf.title}
                     </p>
                     <p className="truncate text-sm text-gray-500">
+                      {wf.tenant && (
+                        <span className="font-medium text-primary-600">{wf.tenant.name}</span>
+                      )}
+                      {wf.tenant && <span> &middot; </span>}
                       {wf._count?.steps ?? wf.steps?.length ?? 0} Schritte &middot; v{wf.version}
                     </p>
                   </div>

frontend/src/pages/WorkflowList.tsx

@@ -1,6 +1,7 @@
 import { useEffect, useState } from 'react';
 import { Link, useSearchParams } from 'react-router-dom';
 import {
+  Building2,
   FileText,
   Grid3X3,
   List,
@@ -8,8 +9,9 @@ import {
   Tag,
 } from 'lucide-react';
 import toast from 'react-hot-toast';
-import { workflowsApi, categoriesApi } from '../services/api';
-import type { Category, Workflow } from '../types';
+import { workflowsApi, categoriesApi, tenantsApi } from '../services/api';
+import { useAuth } from '../hooks/useAuth';
+import type { Category, Tenant, Workflow } from '../types';
 import SearchBar from '../components/SearchBar';
 import StatusBadge from '../components/StatusBadge';
 import Pagination from '../components/Pagination';
@@ -28,12 +30,16 @@ const statusOptions: { value: string; label: string }[] = [
 export default function WorkflowList() {
   const [searchParams, setSearchParams] = useSearchParams();
   const isTemplate = searchParams.get('template') === 'true';
+  const { user } = useAuth();
+  const isAdmin = user?.role === 'SYSTEM_ADMIN' || user?.role === 'TECHNICIAN';
 
   const [workflows, setWorkflows] = useState<Workflow[]>([]);
   const [categories, setCategories] = useState<Category[]>([]);
+  const [tenants, setTenants] = useState<Tenant[]>([]);
   const [search, setSearch] = useState('');
   const [statusFilter, setStatusFilter] = useState('');
   const [categoryFilter, setCategoryFilter] = useState('');
+  const [tenantFilter, setTenantFilter] = useState('');
   const [page, setPage] = useState(1);
   const [totalPages, setTotalPages] = useState(1);
   const [loading, setLoading] = useState(true);
@@ -41,11 +47,14 @@ export default function WorkflowList() {
 
   useEffect(() => {
     categoriesApi.list().then(setCategories).catch(() => {});
-  }, []);
+    if (isAdmin) {
+      tenantsApi.list({ pageSize: 100 }).then((r) => setTenants(r.data)).catch(() => {});
+    }
+  }, [isAdmin]);
 
   useEffect(() => {
     loadWorkflows();
-  }, [search, statusFilter, categoryFilter, page, isTemplate]);
+  }, [search, statusFilter, categoryFilter, tenantFilter, page, isTemplate]);
 
   const loadWorkflows = async () => {
     setLoading(true);
@@ -57,6 +66,7 @@ export default function WorkflowList() {
         status: statusFilter || undefined,
         categoryId: categoryFilter || undefined,
         isTemplate: isTemplate || undefined,
+        tenantId: tenantFilter || undefined,
       };
       const res = await workflowsApi.list(params);
       setWorkflows(res.data);
@@ -130,6 +140,23 @@ export default function WorkflowList() {
               </option>
             ))}
           </select>
+          {isAdmin && tenants.length > 0 && (
+            <select
+              value={tenantFilter}
+              onChange={(e) => {
+                setTenantFilter(e.target.value);
+                setPage(1);
+              }}
+              className="input-field w-auto"
+            >
+              <option value="">Alle Mandanten</option>
+              {tenants.map((t) => (
+                <option key={t.id} value={t.id}>
+                  {t.name}
+                </option>
+              ))}
+            </select>
+          )}
           <div className="flex rounded-lg border border-gray-300 bg-white">
             <button
               onClick={() => setViewMode('grid')}
@@ -190,8 +217,14 @@ export default function WorkflowList() {
                 </h3>
                 <StatusBadge status={wf.status} />
               </div>
+              {wf.tenant && (
+                <div className="mt-2 flex items-center gap-1.5 text-xs font-medium text-primary-600">
+                  <Building2 size={12} />
+                  {wf.tenant.name}
+                </div>
+              )}
               {wf.description && (
-                <p className="mt-2 line-clamp-2 text-sm text-gray-500">
+                <p className="mt-1 line-clamp-2 text-sm text-gray-500">
                   {wf.description}
                 </p>
               )}
@@ -242,11 +275,13 @@ export default function WorkflowList() {
               </div>
               <div className="min-w-0 flex-1">
                 <p className="truncate font-medium text-gray-900">{wf.title}</p>
-                {wf.description && (
                 <p className="truncate text-sm text-gray-500">
+                  {wf.tenant && (
+                    <span className="font-medium text-primary-600">{wf.tenant.name}</span>
+                  )}
+                  {wf.tenant && wf.description && <span> &middot; </span>}
                   {wf.description}
                 </p>
-                )}
               </div>
               {wf.category && (
                 <span className="hidden rounded bg-gray-100 px-2 py-1 text-xs text-gray-600 md:inline">

frontend/src/types/index.ts

@@ -29,6 +29,7 @@ export interface Workflow {
   tags: string[];
   steps?: WorkflowStep[];
   _count?: { steps: number };
+  tenant?: Tenant;
   createdBy: User;
   createdAt: string;
   updatedAt: string;