Standardize on the .agents/ directory (shared with project skills):
phases/, user_stories/, reports/, screenshots/, validate.sh, and
phase-sessions/ + pipeline.log all move to .agents/ (git mv preserves
history; runtime artifacts move alongside).
Updates every reference in AGENTS.md, README.md, .gitignore, app
docstrings, and test story headers. Historical KB content in data/
and the runtime pipeline.log transcript are left untouched.