Rename ci/otelrecv.py to ci/otel-receiver.py for readability.
Replace SIGTERM+wait shutdown (which could hang indefinitely) with an
HTTP-based approach: add GET /shutdown to otel-receiver.py that calls
self.server.shutdown() directly. After dagger call returns, curl that
endpoint so the receiver prints its timing report and exits cleanly.
Cleanup is reduced to a SIGKILL fallback in case the process is already
gone.
Also fix the do_GET handler to reference self.server instead of the
local variable server, which was inaccessible from the handler class.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
