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/tenant_handler_test.go

@@ -456,7 +456,7 @@ func TestTenantHandler_ListTenantsHidesPrivateSubtreeForUnauthorizedUser(t *test
 	app.Use(func(c *fiber.Ctx) error {
 		c.Locals("user_profile", &domain.UserProfileResponse{
 			ID:       "user-1",
-			Role:     domain.RoleTenantAdmin,
+			Role:     "tenant_admin",
 			TenantID: parent("company"),
 		})
 		return c.Next()
@@ -502,7 +502,7 @@ func TestTenantHandler_ListTenantsShowsPrivateSubtreeForManageableTenant(t *test
 	app.Use(func(c *fiber.Ctx) error {
 		c.Locals("user_profile", &domain.UserProfileResponse{
 			ID:       "user-1",
-			Role:     domain.RoleTenantAdmin,
+			Role:     "tenant_admin",
 			TenantID: parent("company"),
 			ManageableTenants: []domain.Tenant{
 				{ID: "private-team", Slug: "private-team"},
@@ -545,7 +545,7 @@ func TestTenantHandler_FilterPrivateTenantsAllowsExplicitPrivatePermission(t *te
 
 	filtered, err := h.filterPrivateTenantsForProfile(context.Background(), tenants, &domain.UserProfileResponse{
 		ID:       "user-1",
-		Role:     domain.RoleTenantAdmin,
+		Role:     "tenant_admin",
 		TenantID: parent("company"),
 	})
 
@@ -1139,7 +1139,7 @@ func TestTenantHandler_ExportTenantsCSV_HidesPrivateSubtreeForUnauthorizedUser(t
 	app.Use(func(c *fiber.Ctx) error {
 		c.Locals("user_profile", &domain.UserProfileResponse{
 			ID:       "user-1",
-			Role:     domain.RoleTenantAdmin,
+			Role:     "tenant_admin",
 			TenantID: parent("company"),
 		})
 		return c.Next()