Fix: Add authentication and admin authorization guards to RolesController

[Ultra-Tech-code]

Closes #966

Overview

This PR addresses a critical authorization gap in the RBAC implementation where the RolesController CRUD endpoints were missing authentication and authorization guards. Previously, these endpoints were reachable by any unauthenticated caller, allowing for potential privilege escalation to administrator.

Changes Made

• Secured Controller: Applied @UseGuards(JwtAuthGuard, RolesGuard) and @Roles('admin') at the RolesController class level.
• Swagger Documentation: Added @ApiBearerAuth() so the Swagger contract reflects the authorization requirement.
• DTO Validation: Replaced loose parameter bindings with CreateRoleDto and UpdateRoleDto (using @IsString, @IsOptional, and @IsUUID({ each: true })), enabling the global ValidationPipe whitelist.
• Audit Logging: Endpoints now extract the actor's context (id/sub, email, ipAddress, and userAgent) from the request and pass it to the RolesService to properly record role and permission changes with the acting principal.
• E2E Testing: Added an e2e test (test/security/roles-rbac.e2e-spec.ts) asserting that POST /roles returns a 401 without a token and a 403 with a non-admin token.

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[RUKAYAT-CODER]

Kindly resolve conflict

[RUKAYAT-CODER]

Thank you for contributing to the project.

[RUKAYAT-CODER]

Thank you for contributing to the project.