Standardize page wrappers, add showSocialShare prop, and add Cmd+K search

- Standardize all page wrappers to use consistent min-h-screen bg-background pattern
- Remove Layout wrapper usage from pages that had it
- Remove page-level SocialShare and headers, move into components
- Add showSocialShare prop to all interactive components for consistent control
- Add Cmd+K / Ctrl+K command palette search across all interactives
- Export allInteractives from InteractiveIndex for reuse

Co-Authored-By: Neeldhara Misra <mail@neeldhara.com>

src/pages/SubtractionGamePage.tsx

@@ -1,7 +1,13 @@
 import SubtractionGame from '@/components/SubtractionGame';
 
 const SubtractionGamePage = () => {
-  return <SubtractionGame />;
+  return (
+    <div className="min-h-screen bg-background">
+      <div className="container mx-auto px-4 py-8">
+        <SubtractionGame showSocialShare={true} />
+      </div>
+    </div>
+  );
 };
 
-export default SubtractionGamePage;
+export default SubtractionGamePage;