Narrow gosec G115 exclusion from repo-wide to specific files

[yeongseon]

Context

PR #13 added a repo-wide //nolint:gosec exclusion for rule G115 (integer overflow in uint32 to int conversion). This is overly broad — only specific files need it.

Problem

The current exclusion suppresses G115 across the entire repo, hiding potential integer overflow issues in future code.

Proposed Fix

1. Identify the exact files/lines that need the G115 exclusion (likely CAS protocol buffer size conversions).
2. Remove the repo-wide exclusion from .golangci.yml or equivalent config.
3. Add //nolint:gosec // G115: CAS protocol field is bounded inline comments at the specific conversion sites.

References

• PR chore: suppress gosec false positives with nosec annotations #13: gosec G115 fix