vllm with --uvicorn-log-level warning suppresses the "Uvicorn running"
banner that the readiness watcher waited for, so the spawn helper hung
forever even after the API was live. Add an HTTP probe in parallel with
the log watcher and broaden the log markers to include vllm's own
"Starting vLLM API server" / "Available routes are" lines.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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