perf(test): fold gateway discover tests into run-loop

src/cli/gateway-cli/run-loop.test.ts

@@ -1,4 +1,6 @@
 import { describe, expect, it, vi } from "vitest";
+import type { GatewayBonjourBeacon } from "../../infra/bonjour-discovery.js";
+import { pickBeaconHost, pickGatewayPort } from "./discover.js";
 
 const acquireGatewayLock = vi.fn(async () => ({
   release: vi.fn(async () => {}),
@@ -140,3 +142,35 @@ describe("runGatewayLoop", () => {
     }
   });
 });
+
+describe("gateway discover routing helpers", () => {
+  it("prefers resolved service host over TXT hints", () => {
+    const beacon: GatewayBonjourBeacon = {
+      instanceName: "Test",
+      host: "10.0.0.2",
+      lanHost: "evil.example.com",
+      tailnetDns: "evil.example.com",
+    };
+    expect(pickBeaconHost(beacon)).toBe("10.0.0.2");
+  });
+
+  it("prefers resolved service port over TXT gatewayPort", () => {
+    const beacon: GatewayBonjourBeacon = {
+      instanceName: "Test",
+      host: "10.0.0.2",
+      port: 18789,
+      gatewayPort: 12345,
+    };
+    expect(pickGatewayPort(beacon)).toBe(18789);
+  });
+
+  it("falls back to TXT host/port when resolve data is missing", () => {
+    const beacon: GatewayBonjourBeacon = {
+      instanceName: "Test",
+      lanHost: "test-host.local",
+      gatewayPort: 18789,
+    };
+    expect(pickBeaconHost(beacon)).toBe("test-host.local");
+    expect(pickGatewayPort(beacon)).toBe(18789);
+  });
+});