fix(types): add aria-hidden to IconProps augment; remove orphaned ShadCN components

- lucide-augment.d.ts: add `aria-hidden?: string | boolean` to IconProps
  (SVGAttributes drops this too in @lucide/svelte ≥ 0.577.0)
- Remove src/lib/components/ui/ — ShadCN primitives with zero importers;
  bits-ui API drift was generating ~20 type errors for dead code

svelte-check: 31 errors remaining (all ModalProps.children — flowbite-svelte
API change, deferred to next session), 0 warnings.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/lucide-augment.d.ts

@@ -21,5 +21,6 @@ export {};
 declare module '@lucide/svelte' {
     interface IconProps {
         class?: string;
+        'aria-hidden'?: string | boolean;
     }
 }