[Bug] WebFetch calls hang indefinitely without timeout

Bug Description
The below, and various other, WebFetch calls hang forever if you leave them alone. Ideally they'd eventually timeout or, even better, fail fast. I suspect it may have to do with the site having a cookie accept/reject prompt, but I'm not sure. Note that this issue spans Claude Code and ClaudeAgentSDK.

Minimally Reproducing Example

Run a web fetch with these parameters:

  {
  "prompt": "Extract a summary",
  "url": "https://www.mckinsey.com/capabilities/strategy-and-corporate-finance/our-insights/done-de
  al-why-many-large-transactions-fail-to-cross-the-finish-line"
  }

Environment Info

• Platform: darwin
• Terminal: ghostty
• Version: 2.1.5
• Feedback ID: b4168281-4e99-46fe-b4c7-c1e1df992eb6

Errors

[{"error":"Error: NON-FATAL: Lock acquisition failed for /Users/stephenmalina/.local/share/claude/versions/2.1.5 (expected in multi-process scenarios)\n    at lhR (/$bunfs/root/claude:2770:2157)\n    at yEA (/$bunfs/root/claude:2770:1268)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-12T17:01:54.828Z"},{"error":"Error\n    at Z (/$bunfs/root/claude:60:4951)\n    at abort (unknown)\n    at dZ (/$bunfs/root/claude:2981:67546)\n    at <anonymous> (/$bunfs/root/claude:2817:7661)\n    at <anonymous> (/$bunfs/root/claude:807:4781)\n    at <anonymous> (/$bunfs/root/claude:807:2520)\n    at H (/$bunfs/root/claude:807:3365)\n    at emit (/$bunfs/root/claude:796:1466)\n    at uwD (/$bunfs/root/claude:801:5036)\n    at <anonymous> (/$bunfs/root/claude:683:108933)\n    at request (/$bunfs/root/claude:62:2149)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-12T17:03:08.163Z"}]

After running for several minutes:

⏺ Fetch(https://www.mckinsey.com/capabilities/strategy-and-corporate-finance/our-insights/done-deal-why-many-large-transactions-fail-to-cross
       -the-finish-line)
  ⎿  Error: canceled