Repair on edits

Status: Partial. General schema repair runs on all tools including edit before validation. Hashline-specific lenient parsing inside @veyyon/hashline remains separate.

When a model emits a malformed edit or apply_patch call:

1. Schema repair attempts JSON recovery and ambiguity refusal at the agent-loop seam.
2. If repair succeeds, arguments proceed to hashline / apply_patch validation and dispatch.
3. If repair cannot disambiguate, the loop returns a loud error with coaching hints (no dispatch).
4. Hashline still tolerates envelope stripping and bare-body piping inside @veyyon/hashline.

See Repair overview and The hashline edit engine.