docs: add Korean runtime agent result guide

[hyeokjun32]

Summary

• add a Korean quick guide for the Runtime agent result contract
• link the English/Korean contract docs from README and README.ko
• add README doc guards for additive Runtime evidence and ownership boundaries

Tests

• git diff --check
• python3 tests/test_readme_docs.py
• python3 tests/test_agent_runtime_result_contract.py
• python3 tests/test_manifest_compare_identity.py
• python3 -m unittest discover -s tests -p 'test_*.py'
• bash scripts/smoke_default.sh

Note: tests that write results/latest.json were run with the approved execution path because sandboxed runs cannot update that generated result file.