Edit a range of lines in a text file via `edit`: `{ "file": file, "edits": [{ "anchor_from": a, "anchor_to": b, "replace_with": text }, ...] }` (arity = edits.length, atomic, one file per call). Use `edit` for content seen via `read` or a diff; never for directories, binaries, or images. `anchor_from`/`anchor_to` are bare 3-char HASH anchors (e.g. "wUp") — copy the 3 chars before `│` in this file's served `HASH│content` lines (lease (session, file, anchor)), never `│` or content. `replace_with` is bare content (`\n` joins lines, `""` deletes; a line reproducing a served row is refused). Example: `{"file":"s.py","edits":[{"anchor_from":"wUp","anchor_to":"AU6","replace_with":"x:\n    y"}]}`. `[MODEL]` in `content` is your retry instruction; dimmed `[USER]` in `details` is human info.