- Added locator-based atom edits with required `loc`, including inline `file:line`, range, and `^`/`$` selectors.
- Added path resolution via top-level path, entry path, or `path:loc` selectors and flattened multi-target atom execution.
- Removed `del`; required `set/pre/post` to use line arrays and mapped `set: []` to deletion semantics.
- Changed `sub` payloads to required `[find, replace]` tuples and tightened parsing to accept null optional verbs and array-or-null lines.