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/src/PnvPanel.Api/Endpoints/AdminInstructionEndpoints.cs

@@ -0,0 +1,68 @@
+using PnvPanel.Api.Common;
+using PnvPanel.Application.Admin.Instructions;
+using PnvPanel.Application.Common.Messaging;
+using PnvPanel.Application.Instructions;
+using PnvPanel.Infrastructure.Identity;
+
+namespace PnvPanel.Api.Endpoints;
+
+public static class AdminInstructionEndpoints
+{
+    public static IEndpointRouteBuilder MapAdminInstructionEndpoints(this IEndpointRouteBuilder app)
+    {
+        var admin = app.MapGroup("/api/admin/instructions")
+            .WithTags("Admin.Instructions")
+            .RequireAuthorization(policy => policy.RequireRole(RoleNames.Admin));
+
+        admin.MapPut("/intro", UpdateIntro).Produces<InstructionIntroDto>();
+        admin.MapPost("/tabs", CreateTab).Produces<InstructionTabDto>();
+        admin.MapPut("/tabs/{id:guid}", UpdateTab).Produces<InstructionTabDto>();
+        admin.MapDelete("/tabs/{id:guid}", DeleteTab).Produces(StatusCodes.Status204NoContent);
+
+        return app;
+    }
+
+    private static async Task<IResult> UpdateIntro(
+        UpdateInstructionIntroCommand command,
+        ISender sender,
+        CancellationToken cancellationToken
+    )
+    {
+        var result = await sender.Send(command, cancellationToken);
+        return result.ToHttpResult();
+    }
+
+    private static async Task<IResult> CreateTab(
+        CreateInstructionTabCommand command,
+        ISender sender,
+        CancellationToken cancellationToken
+    )
+    {
+        var result = await sender.Send(command, cancellationToken);
+        return result.ToHttpResult();
+    }
+
+    private static async Task<IResult> UpdateTab(
+        Guid id,
+        UpdateInstructionTabBody body,
+        ISender sender,
+        CancellationToken cancellationToken
+    )
+    {
+        var command = new UpdateInstructionTabCommand(id, body.Title, body.Body, body.SortOrder);
+        var result = await sender.Send(command, cancellationToken);
+        return result.ToHttpResult();
+    }
+
+    private static async Task<IResult> DeleteTab(
+        Guid id,
+        ISender sender,
+        CancellationToken cancellationToken
+    )
+    {
+        var result = await sender.Send(new DeleteInstructionTabCommand(id), cancellationToken);
+        return result.ToHttpResult();
+    }
+}
+
+public sealed record UpdateInstructionTabBody(string Title, string Body, int SortOrder);

backend/src/PnvPanel.Api/Endpoints/InstructionEndpoints.cs

@@ -0,0 +1,32 @@
+using PnvPanel.Api.Common;
+using PnvPanel.Application.Common.Messaging;
+using PnvPanel.Application.Instructions;
+
+namespace PnvPanel.Api.Endpoints;
+
+public static class InstructionEndpoints
+{
+    public static IEndpointRouteBuilder MapInstructionEndpoints(this IEndpointRouteBuilder app)
+    {
+        var group = app.MapGroup("/api/instructions")
+            .WithTags("Instructions")
+            .RequireAuthorization();
+
+        group.MapGet("/intro", GetIntro).Produces<InstructionIntroDto>();
+        group.MapGet("/tabs", ListTabs).Produces<IReadOnlyList<InstructionTabDto>>();
+
+        return app;
+    }
+
+    private static async Task<IResult> GetIntro(ISender sender, CancellationToken cancellationToken)
+    {
+        var result = await sender.Send(new GetInstructionIntroQuery(), cancellationToken);
+        return result.ToHttpResult();
+    }
+
+    private static async Task<IResult> ListTabs(ISender sender, CancellationToken cancellationToken)
+    {
+        var result = await sender.Send(new ListInstructionTabsQuery(), cancellationToken);
+        return result.ToHttpResult();
+    }
+}

backend/src/PnvPanel.Api/Program.cs

@@ -185,10 +185,12 @@ app.MapConfigEndpoints();
 app.MapSubscriptionEndpoints();
 app.MapAppEndpoints();
 app.MapNewsEndpoints();
+app.MapInstructionEndpoints();
 app.MapAdminUserEndpoints();
 app.MapAdminStatsEndpoints();
 app.MapAdminAppEndpoints();
 app.MapAdminNewsEndpoints();
+app.MapAdminInstructionEndpoints();
 app.MapSupportEndpoints();
 app.MapAdminSupportEndpoints();
 app.MapAdminMaintenanceEndpoints();