docs: sync community documents

[albert20260301]

Summary

• synchronize CODE_OF_CONDUCT.md, LICENSE, and SECURITY.md with the managed workspace templates
• keep this documentation-only correction separate from chore: sync community files #78, which is awaiting review for issue and PR templates

Impact

• aligns public community, licensing, and vulnerability-reporting guidance; no CLI API or runtime behavior changes

Validation

• git diff --check
• byte-for-byte comparison against the managed templates

[albert20260301]

@francoischalifour could you review this?

I picked you because git blame and path history attribute all touched documents to you. CI is pending. The main review focus is that the managed community, license, and security wording is restored without affecting CLI behavior or #78.