test(tools): add codex integration test gated on PATH detection

Skips gracefully if codex is not installed or not authenticated.

Author: priyanshujain

agent/tools/agent_runner_test.go

@@ -213,3 +213,28 @@ func TestAgentRunner_RealGemini(t *testing.T) {
 		t.Error("expected non-empty output")
 	}
 }
+
+func TestAgentRunner_RealCodex(t *testing.T) {
+	if _, err := exec.LookPath("codex"); err != nil {
+		t.Skip("codex not on PATH")
+	}
+	agents := DetectAgents()
+	var info AgentInfo
+	for _, a := range agents {
+		if a.Kind == AgentCodex {
+			info = a
+			break
+		}
+	}
+	r := NewAgentRunner(info)
+	out, err := r.Run(context.Background(), "Say hello in exactly one word.", 30*time.Second)
+	if err != nil {
+		if strings.Contains(err.Error(), "auth") || strings.Contains(err.Error(), "API key") || strings.Contains(err.Error(), "login") {
+			t.Skipf("codex auth not configured: %v", err)
+		}
+		t.Fatalf("Run: %v", err)
+	}
+	if out == "" {
+		t.Error("expected non-empty output")
+	}
+}