Third and last site of the same class. `ReadableStream.cancel()` adopts
the underlying source's cancel promise, which is permitted never to
settle, so awaiting it kept the handler pending forever — and on an
unbounded request there is no timer to release it either. The cancel is
started and the handler returns, so the JSON response and the `finally`
complete regardless.
The `void` carries the justification for which of AGENTS.md's permitted
cases it is: the callee owns its failures through its own `catch`, and
the caller cannot await.
Test: a `/stream-hostile` upstream that sends event-stream headers and
one frame and then never closes, asserting the route still answers 200
with no body.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YFnM6RqB4nXqNysgUYmjmq
Signed-off-by: cliffhall <cliff@futurescale.com>