feat(native): chat tab badge for unread DMs

Adds a tabBarBadge on the bottom Chat tab driven by the same
dm-conversations query the chat screen already uses — React Query
dedupes the call. Badge shows the unread total (capped to "99+")
and disappears when 0. Query is gated on session so unauthenticated
launches don't fire it.

apps/rebreak-native/app/(app)/_layout.tsx

@@ -12,6 +12,9 @@ import { MailConsentReminderSheet } from '../../components/mail/MailConsentRemin
 import { protection } from '../../lib/protection';
 import { preloadTabIcons, getTabIcon } from '../../lib/tabIcons';
 import { apiFetch } from '../../lib/api';
+import { useQuery } from '@tanstack/react-query';
+
+type DmConvUnreadSlice = { unreadCount?: number };
 
 export default function AppLayout() {
   const router = useRouter();
@@ -26,6 +29,17 @@ export default function AppLayout() {
   const rearmInFlightRef = useRef(false);
   const bypassNotifiedRef = useRef(false);
 
+  // Unread DMs → badge on the Chat tab. Same query key chat.tsx uses, so
+  // React Query dedupes (no double fetch when both layouts mount).
+  const { data: dmConvs = [] } = useQuery<DmConvUnreadSlice[]>({
+    queryKey: ['dm-conversations'],
+    queryFn: () => apiFetch('/api/chat/dm-conversations'),
+    staleTime: 30_000,
+    enabled: !!session,
+  });
+  const unreadDms = dmConvs.reduce((sum, c) => sum + (c.unreadCount ?? 0), 0);
+  const chatBadge = unreadDms > 0 ? (unreadDms > 99 ? '99+' : String(unreadDms)) : undefined;
+
   // Android-Tab-Icons müssen async aus Ionicons-Font generiert werden (kein
   // SF-Symbol-Support). preloadTabIcons() läuft schon beim Modul-Import — hier
   // nur den ready-State tracken damit wir re-rendern wenn der Cache fertig ist.
@@ -207,6 +221,7 @@ export default function AppLayout() {
         name="chat"
         options={{
           title: t('tabs.chat'),
+          tabBarBadge: chatBadge,
           tabBarIcon: () =>
             Platform.OS === 'ios'
               ? { sfSymbol: 'bubble.left.and.bubble.right.fill' }

backend/prisma/migrations/20260516_custom_domain_type/migration.sql

@@ -0,0 +1,31 @@
+-- Migration: 20260516_custom_domain_type
+--
+-- Erweitert user_custom_domains um das `type`-Feld.
+-- Drei erlaubte Typen:
+--   'web'               — Web-Domain-Block (bisheriges Verhalten, Default)
+--   'mail_domain'       — Sender-Domain-Block im Mail-Filter (analog web, nutzt Domain-Match-Layer)
+--   'mail_display_name' — Sender-Display-Name-Pattern-Block (Substring-Match, case-insensitive)
+--
+-- Slot-Pool: alle drei Types teilen den gleichen Slot-Pool pro Plan
+--   (Free: 5, Pro: 5, Legend: 10 — countActiveCustomDomains() zählt alle Types zusammen).
+--
+-- DSGVO-Hinweis:
+--   Display-Name-Patterns (type='mail_display_name') sind reine Heuristik-Patterns
+--   die vom User selbst eingetragen werden (z.B. "EXTRASPIN").
+--   Sie gelten NICHT als personenbezogene Daten (Art. 4 DSGVO) —
+--   es handelt sich um selbst-definierte Schlagworte, nicht um identifizierbare PII.
+--   Die Patterns unterliegen dennoch Art. 17 DSGVO (Löschrecht via CASCADE userId).
+--
+-- Non-breaking: alle existierenden Rows erhalten type='web' als Default.
+
+ALTER TABLE rebreak.user_custom_domains
+    ADD COLUMN IF NOT EXISTS type TEXT NOT NULL DEFAULT 'web';
+
+ALTER TABLE rebreak.user_custom_domains
+    ADD CONSTRAINT user_custom_domains_type_check
+    CHECK (type IN ('web', 'mail_domain', 'mail_display_name'));
+
+-- Index für effiziente type-basierte Abfragen pro User
+-- (getCustomMailDisplayNames läuft bei jedem Mail-Scan)
+CREATE INDEX IF NOT EXISTS user_custom_domains_user_type_idx
+    ON rebreak.user_custom_domains (user_id, type);

backend/prisma/schema.prisma

@@ -371,12 +371,17 @@ model UserCustomDomain {
     source  String   @default("manual")
     // "active" | "submitted" | "approved" | "rejected"
     status  String   @default("active")
+    // "web" | "mail_domain" | "mail_display_name"
+    // Alle Types teilen den gleichen Slot-Pool (countActiveCustomDomains() zählt total).
+    // mail_display_name: Substring-Heuristik gegen Sender-Display-Name (kein PII, Art. 4 DSGVO)
+    type    String   @default("web")
     postId  String?  @map("post_id") @db.Uuid
     addedAt DateTime @default(now()) @map("added_at")
 
     submission DomainSubmission?
 
     @@unique([userId, domain])
+    @@index([userId, type])
     @@map("user_custom_domains")
     @@schema("rebreak")
 }