Unify internal hashline edit handling around replace/append/prepend to remove legacy operation shapes. This keeps normalization, ordering, deduplication, execution, and tests aligned with the new op/pos/end/lines contract.
Unify hashline_edit input with replace/append/prepend + pos/end/lines semantics so callers use a single stable shape. Add normalization coverage and refresh tool guidance/tests to reduce schema confusion and stale legacy payload usage.
Keep current field names but accept a pi-style flexible edit payload that is normalized to concrete operations at execution time.
Response now follows concise update/move status with diff metadata retained, removing full-file hashline echo to reduce model feedback loops.
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-opencode)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>