[codex] Complete OpenAI app resubmission packet

[yha9806]

Summary

• Expands the ChatGPT App privacy policy with a per-tool input/output map and clearer data-boundary language.
• Updates the resubmission checklist to cover both OpenAI rejection reasons: privacy policy disclosure and screenshots.
• Adds a screenshot and test-evidence capture plan, then links it from the OpenAI/Codex release gate.

Validation

• PYTHONPATH=src /opt/homebrew/bin/python3.11 -m pytest tests/test_mcp_remote_profile.py -q (16 passed)
• /opt/homebrew/bin/ruff check src/vulca/mcp_remote.py tests/test_mcp_remote_profile.py (passed)
• git diff --check (passed)

Notes

• Keeping this PR as draft until the real production ChatGPT screenshots are captured and uploaded in the OpenAI Platform dashboard.
• Official docs checked: https://developers.openai.com/apps-sdk/deploy/submission and https://developers.openai.com/apps-sdk/app-submission-guidelines.