refactor: move nested skills to root + add ui-ux-pro-max + ConsentOS

- Extract 9 nested skills from website-creator/ to root skills/
- Remove duplicate seo-analyzers, seo-geo, seo-multi-channel from website-creator
- Add new ui-ux-pro-max skill with full UI/UX data
- Update install-skills.sh to sync properly
- Remove .DS_Store artifacts

Moved skills:
- api-and-interface-design
- banner-design
- brand
- design-system
- design
- frontend-ui-engineering
- slides
- spec-driven-development
- ui-styling

skills/slides/references/create.md

@@ -0,0 +1,4 @@
+Invoke `slides` skill to create persuasive HTML slides using design tokens, Chart.js, and the slide knowledge database.
+
+## Task
+<task>$ARGUMENTS</task>