Review fixes for the markdown loop feature:
- Loop-owned tasks now adopt by loop file path, not task name, so renaming
a loop (frontmatter name or UI rename) renames the task in place instead
of leaving a stale duplicate that keeps running the old definition;
orphan duplicates of the same file are unscheduled.
- Unparseable loop files are reported to the scheduler as
definition:null entries: a task whose file still exists is kept with its
last good definition, and only a genuinely removed file unschedules it.
Transiently malformed files (mid-edit, bad merge) no longer delete tasks
or their runtime state.
- Adoption preserves UI-only execution fields (goalEnabled, goalTokenBudget,
permissionAutoAccept, variant) that the portable format does not define.
- DELETE on a loop-sourced task now returns 400 with guidance to remove the
loop file, instead of being silently undone by the next reconcile.
- Loops default to enabled: false; discovery of repository content never
auto-executes scheduled sessions unless the file explicitly enables them.
Regression tests for each fix; DOCUMENTATION.md updated.