What it may solve
Line-anchored read/edit/batch_edit/grep/undo_last_edit tools for DeepSeek Harness (dsh). Every line is addressed by `<line>#<hash>` so chained edits skip a re-read; stale or ambiguous anchors are rejected and a fresh `<line>#<hash>` is served back. Undo p
Imported third-party catalog description; not a Registry verification conclusion.