feat: Stadium Elite Design, Rangliste, Profil-Team, User-Upsert & n8n Cronjob

- MatchCard + TipModal: Uhrzeit statt VS zwischen Flaggen, Gruppe zentriert
- LeaderboardPage: Podium (2./1./3.), DU-Badge, Trend-Pfeile, Team-Zeile, CTA-Card
- AdminPage: Stadium Elite Redesign mit Result-Bar und Inline-Spinner
- ProfilePage: Team-Feld inline editierbar (PATCH /api/profile/team)
- User-Upsert beim ersten App-Aufruf (Matches-Route) statt erst beim Tipp
- DB Migration 002: team-Spalte in users, Leaderboard View aktualisiert
- Leaderboard-Refresh automatisch nach Tipps-Auswertung
- n8n Workflow angelegt: stündlicher Sync + Auswertung (ID: t3SDspIGDXwkfOt3)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/api/client.ts

@@ -39,6 +39,13 @@ export const api = {
   getMyStats: () =>
     request<UserStats>('/leaderboard/me'),
 
+  // Profile
+  updateTeam: (team: string) =>
+    request<{ success: boolean; team: string }>('/profile/team', {
+      method: 'PATCH',
+      body: JSON.stringify({ team }),
+    }),
+
   // Admin
   syncMatches: () =>
     request<{ success: boolean; total: number; created: number; updated: number }>(
@@ -88,6 +95,7 @@ export interface MyTip {
 export interface LeaderboardEntry {
   user_id: string;
   full_name: string;
+  team: string | null;
   total_points: number;
   tips_count: number;
   exact_count: number;
@@ -98,6 +106,7 @@ export interface LeaderboardEntry {
 export interface LeaderboardResponse {
   entries: LeaderboardEntry[];
   currentUserRank: number | null;
+  currentUserId: string | null;
   totalParticipants: number;
   lastUpdated: string;
 }
@@ -105,6 +114,7 @@ export interface LeaderboardResponse {
 export interface UserStats {
   userId: string;
   fullName: string;
+  team: string | null;
   totalPoints: number;
   rank: number | null;
   tipsCount: number;