fix(e2e): fix gen-ai and maas BFF startup failures on self-hosted runners (RHOAIENG-55511) (opendatahub-io#6961)

Two BFF startup issues in the e2e workflow:

1. gen-ai: .env.development contains placeholder URLs like
   `LLAMA_STACK_URL=<your-llama-stack-url>` which the parent Makefile
   exports. The shell interprets `<...>` as a redirect, crashing the BFF.
   Fix: pass explicit empty URL overrides in dev-bff-e2e-cluster, matching
   what dev-bff-e2e-mock already does.

2. maas: The BFF crashes fatally when it cannot auto-discover the K8s
   cluster domain (expected on self-hosted runners outside a cluster).
   Fix: log the error and continue with an empty MaaS API URL, matching
   the graceful pattern used by gen-ai and eval-hub BFFs.

Author: lucferbux

packages/gen-ai/Makefile

@@ -67,7 +67,7 @@ dev-bff-e2e-mock: ## Run BFF for e2e tests (mock mode, no cluster required)
 
 .PHONY: dev-bff-e2e-cluster
 dev-bff-e2e-cluster: ## Run BFF for e2e tests (federated mode, connected to cluster)
-	cd bff && make run PORT=$(E2E_BFF_PORT) LOG_LEVEL=info MOCK_LS_CLIENT=false MOCK_K8S_CLIENT=false MOCK_MAAS_CLIENT=false MOCK_MCP_CLIENT=false MOCK_MLFLOW_CLIENT=false AUTH_METHOD=user_token AUTH_TOKEN_HEADER=x-forwarded-access-token AUTH_TOKEN_PREFIX="" DISTRIBUTION_NAME="rh-dev"
+	cd bff && make run PORT=$(E2E_BFF_PORT) LOG_LEVEL=info MOCK_LS_CLIENT=false MOCK_K8S_CLIENT=false MOCK_MAAS_CLIENT=false MOCK_MCP_CLIENT=false MOCK_MLFLOW_CLIENT=false AUTH_METHOD=user_token AUTH_TOKEN_HEADER=x-forwarded-access-token AUTH_TOKEN_PREFIX="" LLAMA_STACK_URL="" MAAS_URL="" MLFLOW_URL="" DISTRIBUTION_NAME="rh-dev"
 
 .PHONY: dev-start-mock-debug
 dev-start-mock-debug: ## Run frontend and bff (all mocks) with Delve debugger (VSCode: F5 → "Attach to BFF")

packages/maas/bff/internal/api/app.go

@@ -121,11 +121,11 @@ func NewApp(cfg config.EnvConfig, logger *slog.Logger) (*App, error) {
 		if cfg.MaasApiUrl == "" {
 			clusterDomain, err := helper.GetClusterDomainUsingServiceAccount(context.Background(), logger)
 			if err != nil {
-				return nil, fmt.Errorf("automatic discovery of cluster domain failed: %w", err)
+				logger.Error("Failed to auto-discover cluster domain, MaaS API URL will be unavailable", "error", err)
+			} else {
+				cfg.MaasApiUrl = fmt.Sprintf("https://maas.%s/maas-api", clusterDomain)
+				logger.Info("Using automatically discovered MaaS URL", "url", cfg.MaasApiUrl)
 			}
-
-			cfg.MaasApiUrl = fmt.Sprintf("https://maas.%s/maas-api", clusterDomain)
-			logger.Info("Using automatically discovered MaaS URL", "url", cfg.MaasApiUrl)
 		}
 	}