Captures the design rationale for the new overlay-detail Files section
(verify build output, click-to-download for individual files via Flask
send_file, HTMX-driven lazy folder expansion) and the paired
implementation plan that produced it. Adds .superpowers/ to .gitignore
so brainstorm session artifacts never sneak into a future commit.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
