feat(admin-api): 实现 TD-001 和 TD-002 后端接口

TD-001 - PUT /api/admin/v1/tenants/{tenantId}:
- 新增 UpdateTenantCommand + UpdateTenantCommandHandler
- Controller 新增 Update 端点（tenant:update 权限）
- 校验：租户存在、name 非空、name/contactPhone 冲突返回 409
- 仓储扩展：ITenantRepository.ExistsByNameAsync

TD-002 - GET /api/admin/v1/tenants/{tenantId}/quota-usage-history:
- 新增 CQRS Query/Handler/DTO/Validator
- 支持分页（Page>=1, PageSize 1~100）
- 支持时间范围和 QuotaType 过滤
- 新增 tenant_quota_usage_histories 表（含迁移）
- 写入点：CheckTenantQuotaCommandHandler + PurchaseQuotaPackageCommandHandler

构建验证：dotnet build 通过
数据库迁移：已应用 20251218121053_AddTenantQuotaUsageHistories

src/Infrastructure/TakeoutSaaS.Infrastructure/App/Persistence/TakeoutAppDbContext.cs

@@ -59,6 +59,10 @@ public sealed class TakeoutAppDbContext(
     /// </summary>
     public DbSet<TenantQuotaUsage> TenantQuotaUsages => Set<TenantQuotaUsage>();
     /// <summary>
+    /// 租户配额使用历史记录。
+    /// </summary>
+    public DbSet<TenantQuotaUsageHistory> TenantQuotaUsageHistories => Set<TenantQuotaUsageHistory>();
+    /// <summary>
     /// 租户账单。
     /// </summary>
     public DbSet<TenantBillingStatement> TenantBillingStatements => Set<TenantBillingStatement>();
@@ -390,6 +394,7 @@ public sealed class TakeoutAppDbContext(
         ConfigureTenantSubscription(modelBuilder.Entity<TenantSubscription>());
         ConfigureTenantSubscriptionHistory(modelBuilder.Entity<TenantSubscriptionHistory>());
         ConfigureTenantQuotaUsage(modelBuilder.Entity<TenantQuotaUsage>());
+        ConfigureTenantQuotaUsageHistory(modelBuilder.Entity<TenantQuotaUsageHistory>());
         ConfigureTenantBilling(modelBuilder.Entity<TenantBillingStatement>());
         ConfigureTenantPayment(modelBuilder.Entity<TenantPayment>());
         ConfigureTenantNotification(modelBuilder.Entity<TenantNotification>());
@@ -761,6 +766,18 @@ public sealed class TakeoutAppDbContext(
         builder.HasIndex(x => new { x.TenantId, x.QuotaType }).IsUnique();
     }
 
+    private static void ConfigureTenantQuotaUsageHistory(EntityTypeBuilder<TenantQuotaUsageHistory> builder)
+    {
+        builder.ToTable("tenant_quota_usage_histories");
+        builder.HasKey(x => x.Id);
+        builder.Property(x => x.QuotaType).HasConversion<int>();
+        builder.Property(x => x.ChangeType).HasConversion<int>();
+        builder.Property(x => x.ChangeReason).HasMaxLength(256);
+
+        builder.HasIndex(x => new { x.TenantId, x.QuotaType, x.RecordedAt });
+        builder.HasIndex(x => new { x.TenantId, x.RecordedAt });
+    }
+
     private static void ConfigureTenantBilling(EntityTypeBuilder<TenantBillingStatement> builder)
     {
         new TenantBillingStatementConfiguration().Configure(builder);