fix(hackbrowser): guard request.allHeaders() so a closed target can't crash the worker (#104)

The page.on("request", async …) capture handler awaited request.allHeaders() without a
try/catch. In headed mode a page/context/browser can close mid-crawl (a popup/tab closing,
a navigation) while requests are still in flight; allHeaders() then rejects with "Target
page, context or browser has been closed". Because the handler is a fire-and-forget async
listener and the worker installs no unhandledRejection guard, that rejection takes down the
whole worker process (exit 1) — the crawl ends after only a fraction of the target.

Verified from code + repro: allHeaders() is the SOLE unguarded await in the handler (the UI
-context and response branches below are already try/caught); Bun terminates the process on
an unhandled rejection; the worker has no safety net. Wrap the call and drop the capture on
a closed target instead (a request whose headers never arrived isn't a usable capture), with
a debug line naming the in-flight URL for diagnosis. Repro confirms no unhandled rejection
after the fix; 99/99 tests pass.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: Serhatcck

packages/hackbrowser/src/agent.ts

@@ -476,7 +476,15 @@ function setupRequestInterceptor(
     }
 
     const method = request.method()
-    const headers = await request.allHeaders()
+    let headers: Record<string, string>
+    try {
+      headers = await request.allHeaders()
+    } catch {
+      // Target/page/browser closed mid-flight → drop this capture instead of letting the
+      // unhandled rejection crash the worker. (The response branch below is already guarded.)
+      log.debug("request capture dropped — target closed mid-flight", { url })
+      return
+    }
     const postData = request.postData() ?? null
     const raw = buildRawRequest(method, url, headers, postData)