Mem-Client: Dependency Update Smoke Validation

Mem-client dependency/security updates require smoke validation evidence.

Scope:
- Enforce when PR changes mem-client dependencies (`domains/frontend/mem-client/package.json`, lockfiles, patch files, build/runtime deps).

Rules:
1) Include a short smoke-validation note for key flows/build after dependency or CVE-related updates.
2) Validation may be automated commands, manual smoke checks, or both.
3) Note any known residual risk if full coverage is not practical.

Review behavior:
- Return NOT APPROVED only when dependency/security updates have no credible smoke validation evidence.
- Do not block pure metadata/version doc updates with no actual dependency changes.