Add instructions management functionality and update related components

- Introduced new endpoints for managing instruction intros and tabs, allowing admins to create, update, and delete instructional content.
- Enhanced the FactoryResetCommandHandler to include the seeding of instruction data during a factory reset.
- Updated the database schema to include InstructionIntro and InstructionTab entities, with corresponding migrations.
- Improved frontend routing and components to support the new instructions section, including a dedicated page for displaying instructions and tabs.
- Enhanced API documentation to reflect the new instruction management features and their expected request/response formats.
- Added localization support for the new instructions functionality in both Russian and English.

backend/tests/PnvPanel.Application.Tests/Admin/Maintenance/FactoryResetCommandHandlerTests.cs

@@ -21,6 +21,8 @@ public class FactoryResetCommandHandlerTests
     private readonly IFileStorage _fileStorage = Substitute.For<IFileStorage>();
     private readonly IClientAppCatalogSeeder _catalogSeeder =
         Substitute.For<IClientAppCatalogSeeder>();
+    private readonly IInstructionIntroSeeder _instructionIntroSeeder =
+        Substitute.For<IInstructionIntroSeeder>();
 
     [Fact]
     public async Task Handle_WipesEverythingExceptCurrentAdminAndSystemRoles()
@@ -101,6 +103,7 @@ public class FactoryResetCommandHandlerTests
             _gateway,
             _fileStorage,
             _catalogSeeder,
+            _instructionIntroSeeder,
             currentUser
         );
 
@@ -140,5 +143,6 @@ public class FactoryResetCommandHandlerTests
             );
         await _fileStorage.Received(1).DeleteAsync("stored-name", Arg.Any<CancellationToken>());
         await _catalogSeeder.Received(1).SeedIfEmptyAsync(Arg.Any<CancellationToken>());
+        await _instructionIntroSeeder.Received(1).SeedIfEmptyAsync(Arg.Any<CancellationToken>());
     }
 }