feat: simplify RBAC roles and remove dev role switcher

- Simplified RBAC system to two roles: super_admin and user.
- Removed tenant_admin and rp_admin roles across backend and frontend.
- Removed Dev Role Switcher feature from adminfront.
- Updated all handlers, middlewares, and navigation to reflect the new role model.
- Fixed backend build errors and updated tests.

backend/internal/handler/auth_handler.go

@@ -4744,7 +4744,7 @@ func (h *AuthHandler) hydrateResolvedProfile(ctx context.Context, profile *domai
 	}
 
 	if h.TenantService != nil {
-		if profile.Role == domain.RoleTenantAdmin {
+		if profile.Role == "tenant_admin" {
 			manageable, err := h.TenantService.ListManageableTenants(ctx, profile.ID)
 			if err == nil {
 				profile.ManageableTenants = manageable