since I like making a single file for planning before making beads/todo/issues, then the problem where the llm struggles with:

1. a large file or/and 2. I want to use async agent but conflicting edits etc are a pain 3. creating too many markdown files etc

this basically attempts on solving all of these through a prompt-based harness.

it uses markdown AST, so no need to use lines range, so more precise, and it also has summaries + other bell and whistle