fix(skills): remove phantom resource references and fix CoC links (#447)

Remove references to non-existent resource files (references/, assets/,
scripts/, examples/) from 115 skill SKILL.md files. These sections
pointed to directories and files that were never created, causing
confusion when users install skills.

Also fix broken Code of Conduct links in issue templates to use
absolute GitHub URLs instead of relative paths that 404.

plugins/ui-design/skills/design-system-patterns/SKILL.md

@@ -327,11 +327,3 @@ module.exports = {
 - **Hardcoded Values**: Using raw values instead of tokens
 - **Circular References**: Tokens referencing each other in loops
 - **Platform Gaps**: Tokens missing for some platforms (web but not mobile)
-
-## Resources
-
-- [Style Dictionary Documentation](https://amzn.github.io/style-dictionary/)
-- [Tokens Studio for Figma](https://tokens.studio/)
-- [Design Tokens W3C Spec](https://design-tokens.github.io/community-group/format/)
-- [Radix UI Themes](https://www.radix-ui.com/themes)
-- [shadcn/ui Theming](https://ui.shadcn.com/docs/theming)