feat: add command palette, accessibility, scroll animations, and keyboard navigation

Implements COMP-139 (command palette), COMP-140 (accessibility), COMP-141 (scroll animations), COMP-145 (keyboard navigation)

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-Claude)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

apps/web/src/components/scroll-section.tsx

@@ -0,0 +1,28 @@
+"use client";
+
+import { useScrollAnimate } from "@/hooks/use-scroll-animate";
+
+interface ScrollSectionProps {
+  children: React.ReactNode;
+  className?: string;
+  delay?: number;
+}
+
+export function ScrollSection({
+  children,
+  className = "",
+  delay,
+}: ScrollSectionProps) {
+  const ref = useScrollAnimate<HTMLDivElement>();
+
+  return (
+    <div
+      ref={ref}
+      data-animate="hidden"
+      data-animate-delay={delay}
+      className={className}
+    >
+      {children}
+    </div>
+  );
+}