Boot the real dsh web tree against an in-test OTLP/HTTP collector and a
mock LLM server, drive one turn over /api, then SIGINT. Asserts the wire:
OTLP JSON structure and resource identity, both instrumentation scopes,
ledger event coverage in seq order, prompt fidelity in the exported body,
the first-of-step chunk projection, and the ops shutdown marker arriving
through the exit drain.
