fix: decode console output to ensure tracebacks are detected even when encoded

__tests__/monitor.test.js

@@ -482,4 +482,26 @@ describe("monitorConsole", () => {
     // We expect it to have called api.time fewer than 10 times (excluding the startTick call)
     expect(api.time.mock.calls.length).toBeLessThan(10);
   });
+
+  it("detects encoded tracebacks in log lines", async () => {
+    const api = buildMockApi({ ticks: [100, 101, 102] });
+    setTimeout(() => {
+      api._fireConsole({
+        messages: {
+          log: [
+            "Error: ReferenceError: a is not defined%0A    at eval (eval at <anonymous> (_console1778948572008_0:1:46), <anonymous>:1:1)%0A    at _console1778948572008_0:1:46",
+          ],
+          results: [],
+        },
+        error: null,
+      });
+    }, 50);
+
+    const result = await monitorConsole(api, {
+      ...BASE_OPTS,
+      onTraceback: "fail",
+    });
+    expect(result.sawTraceback).toBe(true);
+    expect(result.sawErrorLog).toBe(true);
+  });
 });