Document SCML and CybORG smoke checks

[Muhtasham]

Summary

• Adds a reviewer-facing smoke-test section to the SCML arena docs with the exact dummy-player command, expected log/metadata artifacts, and expected score object shape.
• Adds the same smoke-test section to the CybORG arena docs, including the per-episode status: "ok" / steps_completed detail shape.
• Clarifies that the embedded score snippets are representative metadata examples, not stable golden values, because simulation order/configuration and CybORG randomness can change exact dummy scores.

Why

This makes the newly merged SCML and CybORG arenas easier to sanity-check after pulling main: a reviewer can run one command per arena and verify validation, player-name mapping, scoring, and log artifact generation without reading the runtime code first.

Verification

• uv run python main.py configs/examples/SCML__dummy__r1__s2.yaml -o /tmp/codeclash-scml-smoke
  • passed; both players validated; round summaries produced floating-point alpha / beta scores and metadata/log artifacts.
• uv run python main.py configs/examples/CybORG__dummy__r1__s2.yaml -o /tmp/codeclash-cyborg-smoke
  • passed; both players validated; per-episode details had status: "ok" and steps_completed: 5; metadata/log artifacts were written.
• uv run pre-commit run --files docs/reference/arenas/scml.md docs/reference/arenas/cyborg.md
• uv run mkdocs build
• git diff --check

Notes

• This is docs-only; no runtime/config behavior changes.
• The docs tell reviewers to use a fresh -o directory when rerunning smoke checks instead of deleting output directories.