test(cli): add coverage for port scan fallback and c8 ignore for signal handlers

Adds test for stopDashboard finding an orphaned dashboard on a reassigned
port via the port-range scan fallback. Marks signal handler body with
c8 ignore since it only fires on process termination.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/cli/__tests__/commands/start.test.ts

@@ -1059,6 +1059,7 @@ describe("stop command", () => {
     mockConfigRef.current = makeConfig({ "my-app": makeProject() });
     mockSessionManager.get.mockResolvedValue({ id: "app-orchestrator", status: "running" });
     mockSessionManager.kill.mockResolvedValue(undefined);
+    mockExec.mockResolvedValue({ stdout: "12345", stderr: "" });
 
     await program.parseAsync(["node", "test", "stop", "--purge-session"]);
 
@@ -1066,6 +1067,27 @@ describe("stop command", () => {
       purgeOpenCode: true,
     });
   });
+
+  it("finds orphaned dashboard on a reassigned port via port scan", async () => {
+    mockConfigRef.current = makeConfig({ "my-app": makeProject() });
+    mockSessionManager.get.mockResolvedValue({ id: "app-orchestrator", status: "running" });
+    mockSessionManager.kill.mockResolvedValue(undefined);
+    // Port 3000 has nothing, but port 3001 has the orphaned dashboard
+    mockExec.mockImplementation(async (cmd: string, args: string[] = []) => {
+      if (cmd === "kill") return { stdout: "", stderr: "" };
+      const portArg = args.find((a) => a.startsWith(":"));
+      if (portArg === ":3001") return { stdout: "99999", stderr: "" };
+      throw new Error("no process");
+    });
+
+    await program.parseAsync(["node", "test", "stop"]);
+
+    const output = vi
+      .mocked(console.log)
+      .mock.calls.map((c) => c.join(" "))
+      .join("\n");
+    expect(output).toContain("was on port 3001");
+  });
 });
 
 // ---------------------------------------------------------------------------

packages/cli/src/commands/start.ts

@@ -1155,6 +1155,7 @@ async function runStartup(
 
     // Ensure the dashboard child is killed when the parent exits (e.g. Ctrl+C).
     // Node.js does not guarantee signal propagation to child processes.
+    /* c8 ignore start -- signal handlers only fire on process termination */
     const killDashboard = (): void => {
       try {
         dashboardProcess?.kill("SIGTERM");
@@ -1162,6 +1163,7 @@ async function runStartup(
         // already dead
       }
     };
+    /* c8 ignore stop */
     process.on("SIGINT", killDashboard);
     process.on("SIGTERM", killDashboard);
     process.on("exit", killDashboard);