fix: add Tailwind theme color variables guideline (#10)

- Add guideline to use bg-primary instead of bg-[var(--color-primary)]
- Add checklist item in SKILL.md Pre-Delivery Checklist
- Sync html-tailwind.csv to .shared folder

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude <noreply@anthropic.com>

.claude/skills/ui-ux-pro-max/SKILL.md

@@ -201,6 +201,7 @@ Before delivering UI code, verify these items:
 - [ ] All icons from consistent icon set (Heroicons/Lucide)
 - [ ] Brand logos are correct (verified from Simple Icons)
 - [ ] Hover states don't cause layout shift
+- [ ] Use theme colors directly (bg-primary) not var() wrapper
 
 ### Interaction
 - [ ] All clickable elements have `cursor-pointer`