Problem: tasks only have a one-line description. There is no way to
attach extended notes, checklists, or context to a task.
Solution: add `ge` keymap to open a `pending://task/<id>` markdown
buffer that replaces the task list in the same split. The buffer shows
a read-only metadata header (status, priority, category, due,
recurrence) rendered via extmarks, a `---` separator, and editable
notes below. `:w` saves notes to a new top-level `notes` field on the
task stored in the single `tasks.json`. `q` returns to the task list.
Barrett Ruth
d7d79b5b87
