Add the missing code of conduct to cas-reference-product

[OgeonX-Ai]

Summary

Adds the missing CODE_OF_CONDUCT.md file so the repository matches the governance baseline used across the rest of the CAS portfolio.

Changes

• Add CODE_OF_CONDUCT.md at the repository root
• Define expected behavior, unacceptable behavior, and enforcement guidance
• Keep the policy aligned with the other CAS repository governance documents

Why

The repository already had contribution and security guidance but was missing a code of conduct, making it the main portfolio governance outlier.

Validation

• Verified CODE_OF_CONDUCT.md now exists in the repository root
• Confirmed the change is isolated to the new governance file
• No code, build, or test behavior changed

Risks

Low risk. This is a documentation-only governance addition.

Related

• Portfolio-wide CAS documentation and Pages consistency audit

Reviewer notes

Start with the new CODE_OF_CONDUCT.md file. This PR intentionally avoids the unrelated local README and WIKI drift in the existing checkout.