Close the 0.9.3 UI polish milestone

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.

docs/screen-design-report.md

@@ -3,9 +3,9 @@
 Date: 2026-11-02
 Model: automatic cheapest image+JSON selection (`z-ai/glm-5.3-flash` at run time)
 Command: `python3 tools/screen_designs.py judge`
-Result: **13/13 match, 0 review, 0 diff**
+Result: **21/21 match, 0 review, 0 diff**
 
-The screenshot gallery was regenerated on the current build before judging.
+The screenshot gallery was regenerated on the current build before judging, including the eight UI-state captures 14–21 added in `src/test/capture_ui_states.gd`.
 Accepted captures are in [`docs/screens/`](screens/README.md); the committed
 gallery is in [`docs/screenshots/`](screenshots/README.md).