Implement pricing management functionality and update related components

- Added new endpoints for managing global pricing settings, including retrieval and updates for `PricePerConfigPerQuarter` and `PricePerConfigPerYear`.
- Updated `RoleService` and related commands to remove pricing fields from role management, ensuring a clear separation between role configurations and global pricing.
- Enhanced the `FactoryResetCommandHandler` to include seeding of pricing settings during a factory reset.
- Modified frontend components to support new pricing settings, including forms for creating and updating pricing information.
- Updated API documentation to reflect changes in pricing management endpoints and their expected request/response formats.
- Adjusted tests to ensure proper coverage for new pricing functionalities and their integration with existing role management features.

backend/src/PnvPanel.Application/Common/Interfaces/IAppDbContext.cs

@@ -8,6 +8,7 @@ using PnvPanel.Domain.Inbounds;
 using PnvPanel.Domain.Instructions;
 using PnvPanel.Domain.News;
 using PnvPanel.Domain.Nodes;
+using PnvPanel.Domain.Pricing;
 using PnvPanel.Domain.Support;
 using PnvPanel.Domain.Telegram;
 
@@ -45,6 +46,8 @@ public interface IAppDbContext
 
     DbSet<InstructionTab> InstructionTabs { get; }
 
+    DbSet<PricingSettings> PricingSettings { get; }
+
     /// <summary>Нужен для advisory-lock при проверке квоты конфигов (см. CreateVpnConfigCommandHandler).</summary>
     DatabaseFacade Database { get; }
 

backend/src/PnvPanel.Application/Common/Interfaces/IPricingSettingsSeeder.cs

@@ -0,0 +1,10 @@
+namespace PnvPanel.Application.Common.Interfaces;
+
+/// <summary>
+/// Сидинг дефолтной (пустой) строки глобальных настроек цены. Идемпотентно — не трогает таблицу, если
+/// в ней уже есть строка (используется и при старте, и после полного сброса панели).
+/// </summary>
+public interface IPricingSettingsSeeder
+{
+    Task SeedIfEmptyAsync(CancellationToken cancellationToken);
+}

backend/src/PnvPanel.Application/Common/Interfaces/IRoleService.cs

@@ -2,15 +2,7 @@ using PnvPanel.Application.Common.Models;
 
 namespace PnvPanel.Application.Common.Interfaces;
 
-public sealed record RoleDto(
-    Guid Id,
-    string Name,
-    int MaxConfigs,
-    int MaxIpLimit,
-    bool IsSystem,
-    int? PricePerConfigPerQuarter = null,
-    int? PricePerConfigPerYear = null
-);
+public sealed record RoleDto(Guid Id, string Name, int MaxConfigs, int MaxIpLimit, bool IsSystem);
 
 public interface IRoleService
 {
@@ -18,8 +10,6 @@ public interface IRoleService
         string name,
         int maxConfigs,
         int maxIpLimit,
-        int? pricePerConfigPerQuarter,
-        int? pricePerConfigPerYear,
         CancellationToken cancellationToken
     );
 
@@ -27,8 +17,6 @@ public interface IRoleService
         Guid roleId,
         int maxConfigs,
         int maxIpLimit,
-        int? pricePerConfigPerQuarter,
-        int? pricePerConfigPerYear,
         CancellationToken cancellationToken
     );