Harden the current code's failure paths. Follow the error-handling page named from AGENTS.md and existing error/logger packages. Do not hide the owning failure with retries.
- Identify failure points on the changed path: validation, I/O, authz, empty/invalid input.
- Use the repo error type and logger. Return or render existing user-facing error patterns.
- Retry only when the write is replay-safe. Otherwise keep an explicit no-retry path with a bounded deadline if a retry is already required.
- Cover the new path with a test or a named manual scenario. Run the smallest existing check.
- Docs:
/w-docsif behavior or commands changed.
