XY-885: [ELF benchmark adapter] Implement RAGFlow Docker evidence-smoke adapter

[yvette-carlisle]

Summary

• Add scripts/ragflow-docker-evidence-smoke.sh, a Docker-contained RAGFlow evidence smoke that defaults to a typed preflight and only starts the official RAGFlow Docker Compose stack with explicit resource-envelope opt-in.
• Add cargo make ragflow-docker-smoke as the repo-native entrypoint.
• Keep the checked-in RAGFlow manifest as research_gate; generated smoke artifacts can become live_real_world only after query output returns reference chunks mapped to generated evidence ids.

Verification

• cargo make ragflow-docker-smoke
• generated sidecar manifest accepted by real_world_job_benchmark with typed blocked / research_gate state
• default external adapter manifest report preserved RAGFlow as research_gate
• cargo test -p elf-eval --test real_world_job_benchmark --all-features
• cargo make fmt
• cargo make lint-fix
• cargo make checks