feat: Add EF configurations and migration for network-club system

EF Core Configurations (11 files):
- SystemConfigurationConfiguration with Scope+Key composite index
- ClubMembershipConfiguration with one-to-one User relationship
- ClubFeatureConfiguration with IsActive+SortOrder index
- UserClubFeatureConfiguration with composite unique index
- NetworkWeeklyBalanceConfiguration with UserId+WeekNumber index
- WeeklyCommissionPoolConfiguration with unique WeekNumber
- UserCommissionPayoutConfiguration with multiple indexes
- ClubMembershipHistoryConfiguration for audit trail
- NetworkMembershipHistoryConfiguration for audit trail
- CommissionPayoutHistoryConfiguration for audit trail
- SystemConfigurationHistoryConfiguration for audit trail

Configuration Updates:
- UserConfiguration: Add NetworkParentId, LegPosition with indexes
- UserWalletConfiguration: Add DiscountBalance field
- ProductsConfiguration: Add IsClubExclusive, ClubDiscountPercent with index

Infrastructure Updates:
- ApplicationDbContext: Add 11 new DbSets for network-club entities
- GlobalUsings: Add Domain entity namespaces

Migration:
- AddNetworkClubSystemV2: Complete database schema for network-club system

src/CMSMicroservice.Infrastructure/Persistence/ApplicationDbContext.cs

@@ -60,4 +60,25 @@ public class ApplicationDbContext :  DbContext, IApplicationDbContext
     public DbSet<UserOrder> UserOrders => Set<UserOrder>();
     public DbSet<UserWallet> UserWallets => Set<UserWallet>();
     public DbSet<UserWalletChangeLog> UserWalletChangeLogs => Set<UserWalletChangeLog>();
+    
+    // ============= Network Club System DbSets =============
+    
+    // Configuration
+    public DbSet<SystemConfiguration> SystemConfigurations => Set<SystemConfiguration>();
+    public DbSet<SystemConfigurationHistory> SystemConfigurationHistories => Set<SystemConfigurationHistory>();
+    
+    // Club Management
+    public DbSet<ClubMembership> ClubMemberships => Set<ClubMembership>();
+    public DbSet<ClubFeature> ClubFeatures => Set<ClubFeature>();
+    public DbSet<UserClubFeature> UserClubFeatures => Set<UserClubFeature>();
+    public DbSet<ClubMembershipHistory> ClubMembershipHistories => Set<ClubMembershipHistory>();
+    
+    // Network
+    public DbSet<NetworkWeeklyBalance> NetworkWeeklyBalances => Set<NetworkWeeklyBalance>();
+    public DbSet<NetworkMembershipHistory> NetworkMembershipHistories => Set<NetworkMembershipHistory>();
+    
+    // Commission
+    public DbSet<WeeklyCommissionPool> WeeklyCommissionPools => Set<WeeklyCommissionPool>();
+    public DbSet<UserCommissionPayout> UserCommissionPayouts => Set<UserCommissionPayout>();
+    public DbSet<CommissionPayoutHistory> CommissionPayoutHistories => Set<CommissionPayoutHistory>();
 }