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/web-component-design/SKILL.md

@@ -269,11 +269,3 @@ const isActive = computed(() => tabs?.activeTab.value === props.id);
 - **Re-render Cascades**: Profile with React DevTools, memo appropriately
 - **Accessibility Gaps**: Test with screen readers and keyboard navigation
 - **Bundle Size**: Tree-shake unused component variants
-
-## Resources
-
-- [React Component Patterns](https://reactpatterns.com/)
-- [Vue Composition API Guide](https://vuejs.org/guide/reusability/composables.html)
-- [Svelte Component Documentation](https://svelte.dev/docs/svelte-components)
-- [Radix UI Primitives](https://www.radix-ui.com/primitives)
-- [shadcn/ui Components](https://ui.shadcn.com/)