Bmad Sprint Planning

This generates and maintains a sprint-status.yaml file by parsing your epic documents and detecting which stories already have files in your implementation artifacts folder. It handles both monolithic epics.md files and sharded epic structures, extracts story IDs, converts them to kebab-case keys, and assigns statuses based on what exists on disk. Stories get bumped from backlog to ready-for-dev automatically when their markdown file exists. The status detection is smart enough to preserve more advanced statuses if they already exist, so it never downgrades a story from done back to ready-for-dev. Good for teams tracking work in markdown files who want a single source of truth without manually updating YAML every time they create a story file.