fix: clamp copilot auth refresh overflow (#55360) (thanks @michael-abdo)

src/agents/runtime-auth-refresh.test.ts

@@ -0,0 +1,24 @@
+import { describe, expect, it } from "vitest";
+import { clampRuntimeAuthRefreshDelayMs } from "./runtime-auth-refresh.js";
+
+describe("clampRuntimeAuthRefreshDelayMs", () => {
+  it("clamps far-future refresh delays to a timer-safe ceiling", () => {
+    expect(
+      clampRuntimeAuthRefreshDelayMs({
+        refreshAt: 12_345_678_901_000,
+        now: 0,
+        minDelayMs: 60_000,
+      }),
+    ).toBe(2_147_483_647);
+  });
+
+  it("still respects the configured minimum delay", () => {
+    expect(
+      clampRuntimeAuthRefreshDelayMs({
+        refreshAt: 1_000,
+        now: 900,
+        minDelayMs: 60_000,
+      }),
+    ).toBe(60_000);
+  });
+});