fix: bound browser scenario initial navigation during startup

docs/browser-scenario-contract.md

@@ -27,10 +27,12 @@ Duration, action, and navigation timeouts remain separate from CDP command
 deadlines. `command_timeout_ms` (default 20000; omit it to keep that default
 and leave it out of Evidence) bounds launch startup, the connect-over-CDP
 handshake, target lookup, environment commands, and storage CDP commands,
-including replies from attached child targets. Set it in the scenario JSON.
+including replies from attached child targets. It also bounds the initial
+`start_url` navigation through the load event; a redirect or replacement
+navigation cannot leave startup waiting indefinitely. Set it in the scenario JSON.
 `capture-browser-scenario` has no `--command-timeout-ms` option.
 It does not change action `timeout_ms`, `wait_for_timeout.duration_ms`, or
-navigation. Service-worker restoration keeps a fixed 5000 ms grace and does
+action navigation. Service-worker restoration keeps a fixed 5000 ms grace and does
 not inherit a raised `command_timeout_ms`. CDP discovery stays on its own
 fixed deadline. When service workers are blocked, the registration check
 before discovery has its own fixed 10000 ms deadline; `command_timeout_ms`

src/browser/PlaywrightScenarioSession.test.ts

@@ -1453,3 +1453,34 @@ it("retains late opening failure cleanup after cancellation until the exact prof
     await provider.close();
   }
 });
+
+it.each(["launch", "connect"] as const)(
+  "bounds never-settling initial navigation and awaits %s cleanup",
+  async (mode) => {
+    vi.useFakeTimers();
+    const { cleanup, page, storage } = fixture();
+    const request = browserScenarioSchema.parse({
+      ...(mode === "launch" ? scenario : connectedScenario("allow")),
+      command_timeout_ms: 250,
+    });
+    page.goto.mockImplementation(() => new Promise<never>(() => {}));
+    try {
+      const opening = PlaywrightScenarioSession.open(request, {}, {}).catch(
+        (cause: unknown) => cause,
+      );
+      await vi.advanceTimersByTimeAsync(250);
+      const failure = await opening;
+      expect(failure).toMatchObject({
+        _tag: "AnalysisTimeoutError",
+        operation: "capture_browser_scenario",
+        timeoutMs: 250,
+      });
+      expect(cleanup.close).toHaveBeenCalledOnce();
+      expect(storage?.close).toHaveBeenCalledWith(true);
+      expect(page.goto).toHaveBeenCalledOnce();
+    } finally {
+      await cleanup.cleanupLease.release();
+      vi.useRealTimers();
+    }
+  },
+);

src/browser/PlaywrightScenarioSession.ts

@@ -221,7 +221,7 @@ export class PlaywrightScenarioSession implements BrowserScenarioSessionPort {
             waitUntil: "load",
             timeout: 0,
           }),
-        undefined,
+        scenario.command_timeout_ms,
         options.signal,
       );
       await withPlaywrightExecutionBoundary(