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/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();