A provider whose backend keeps the response open without finishing (hanging
HTTP server, stuck SDK call) stalled the web_extract tool call — and with a
sync provider, the borrowed thread — indefinitely. The dispatch in
tools/web_tools_extract._dispatch_extract now runs under asyncio.wait_for with
web.extract_timeout (config.yaml, default 120s; 0 disables). On timeout the
tool returns structured per-URL error entries, and the one-shot keyless rescue
still gets its chance when eligible.
Salvaged from PR #57180 by @liuhao1024 (base predated the web_tools
decomposition; re-applied at the _dispatch_extract seam, env-var timeout
replaced with the web.* config section per the .env-is-for-secrets rule, and
the timeout path made rescue-aware).
Inspired by Claude Code 2.1.268: "Fixed WebFetch hanging indefinitely on a
server that keeps the response open without finishing; a fetch now fails
after 300 seconds."
Fixes#57155
Co-authored-by: liuhao1024 <sunsky.lau@gmail.com>