feat: F025 button & action logic audit — global toast, confirm dialog, wired mutations

- Add ToastProvider (global MUI Snackbar stack) + toastStore (Zustand)
- Add ConfirmDialog reusable component for destructive actions
- Wire toast feedback to all async mutations: review status, AI output status,
  match approval, shortlist add/remove/title/finalize, signal review actions
- Fix dead UserMenu buttons (Profil, Einstellungen) — show info toast
- Migrate local Snackbar instances in AddToShortlistDialog and
  FutureSignalDetailPanel to global toast store

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

src/components/match-center/MatchBriefingPanel.tsx

@@ -4,6 +4,7 @@ import { useMatchesByProperty, useApproveMatch } from '../../hooks/useMatches'
 import { usePropertyById } from '../../hooks/useProperties'
 import { useMatchCenterStore } from '../../stores/matchCenterStore'
 import { useCompareStore } from '../../stores/compareStore'
+import { useToastStore } from '../../stores/toastStore'
 import { MatchCardExpanded } from '../match-card/MatchCardExpanded'
 import { buildMatchCardViewModel } from '../../features/matching/matchCardAdapter'
 import { reviewService } from '../../services/reviewService'
@@ -17,6 +18,7 @@ export function MatchBriefingPanel() {
   const { selectedPropertyId, selectedNeedId } = useMatchCenterStore()
   const { addToCompare } = useCompareStore()
   const approveMatch = useApproveMatch()
+  const showToast = useToastStore((s) => s.showToast)
 
   const { data: matches = [], isLoading: matchesLoading } = useMatchesByProperty(selectedPropertyId ?? '')
   const { data: property = null, isLoading: propLoading } = usePropertyById(selectedPropertyId)
@@ -52,7 +54,10 @@ export function MatchBriefingPanel() {
       label: 'Genehmigen',
       actionType: 'APPROVE',
       variant: 'primary',
-      onClick: () => approveMatch.mutate(match.id),
+      onClick: () => approveMatch.mutate(match.id, {
+        onSuccess: () => showToast('Match genehmigt.'),
+        onError: () => showToast('Genehmigung fehlgeschlagen.', 'error'),
+      }),
     },
     {
       id: 'review',