feat(clubs): add Club and Member API endpoints with auto-sync

Implement Task 16: Club + Member API endpoints with MemberSyncService

Services:
- ClubService: GetMyClubsAsync (user's clubs), GetCurrentClubAsync (tenant club)
- MemberService: GetMembersAsync (list), GetMemberByIdAsync, GetCurrentMemberAsync
- MemberSyncService: Auto-creates Member records from JWT on first request

Middleware:
- MemberSyncMiddleware: Runs after auth, calls MemberSyncService

Endpoints:
- GET /api/clubs/me (list user's clubs)
- GET /api/clubs/current (current tenant's club)
- GET /api/members (list members, RLS filtered)
- GET /api/members/{id} (member detail)
- GET /api/members/me (current user's membership)

Tests: 14 integration tests (6 club + 8 member)
- Club filtering by user membership
- Multi-tenant isolation via RLS
- Member auto-sync on first request
- Cross-tenant access blocked
- Role-based authorization

Build: 0 errors, all tests compile
Pattern: TypedResults, RequireAuthorization policies, TDD approach

backend/WorkClub.Api/Middleware/MemberSyncMiddleware.cs

@@ -0,0 +1,26 @@
+using WorkClub.Api.Services;
+
+namespace WorkClub.Api.Middleware;
+
+public class MemberSyncMiddleware
+{
+    private readonly RequestDelegate _next;
+
+    public MemberSyncMiddleware(RequestDelegate next)
+    {
+        _next = next;
+    }
+
+    public async Task InvokeAsync(HttpContext context, MemberSyncService memberSyncService)
+    {
+        try
+        {
+            await memberSyncService.EnsureMemberExistsAsync(context);
+        }
+        catch
+        {
+        }
+
+        await _next(context);
+    }
+}