Add deterministic captures 14-21 for the remaining screen-design states, fix the panel/button layout issues they exposed, and record 21/21 compare and judge results. Bump the source to 0.9.3 and move the completed milestone to DONE.md.
Both capture helpers now accept --out=res://docs/screenshots, and
tools/check_screenshots.sh renders the staged set (using xvfb-run when headless)
before running screen_designs.py compare. Record the judge result: 7 match,
4 review, 0 diff. Headless 226/226 and the smoke both pass in a clean worktree.
zwitschi