feat(ui): Liquid Glass + Aceternity 컴포넌트 도입 (clsx·framer-motion·tailwind-merge)

- LiquidGlass: GlassButton·GlassFilter (Apple Liquid Glass 효과)
- 3d-card-effect: 마우스 추적 3D 카드 래퍼
- sparkles-text: SparklesText·SparklesOverlay
- lib/utils.ts: cn() (clsx + tailwind-merge)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

app/components/LiquidGlass.tsx

@@ -0,0 +1,161 @@
+'use client';
+
+import React from 'react';
+import Link from 'next/link';
+
+interface GlassEffectProps {
+  children: React.ReactNode;
+  className?: string;
+  style?: React.CSSProperties;
+  href?: string;
+  external?: boolean;
+  target?: string;
+  onClick?: () => void;
+  tint?: string;
+}
+
+export const GlassEffect: React.FC<GlassEffectProps> = ({
+  children,
+  className = '',
+  style = {},
+  href,
+  external,
+  target,
+  onClick,
+  tint = 'rgba(255, 255, 255, 0.18)',
+}) => {
+  const glassStyle: React.CSSProperties = {
+    boxShadow: '0 6px 6px rgba(0, 0, 0, 0.2), 0 0 20px rgba(0, 0, 0, 0.1)',
+    transitionTimingFunction: 'cubic-bezier(0.175, 0.885, 0.32, 2.2)',
+    ...style,
+  };
+
+  const content = (
+    <div
+      className={`relative flex font-semibold overflow-hidden text-white cursor-pointer transition-all duration-700 ${className}`}
+      style={glassStyle}
+      onClick={onClick}
+    >
+      <div
+        className="absolute inset-0 z-0 overflow-hidden"
+        style={{
+          borderRadius: 'inherit',
+          backdropFilter: 'blur(3px)',
+          WebkitBackdropFilter: 'blur(3px)',
+          filter: 'url(#glass-distortion)',
+          isolation: 'isolate',
+        }}
+      />
+      <div
+        className="absolute inset-0 z-10"
+        style={{ borderRadius: 'inherit', background: tint }}
+      />
+      <div
+        className="absolute inset-0 z-20 overflow-hidden"
+        style={{
+          borderRadius: 'inherit',
+          boxShadow:
+            'inset 2px 2px 1px 0 rgba(255,255,255,0.5), inset -1px -1px 1px 1px rgba(255,255,255,0.5)',
+        }}
+      />
+      <div className="relative z-30 w-full">{children}</div>
+    </div>
+  );
+
+  if (!href) return content;
+  if (external) {
+    return (
+      <a
+        href={href}
+        target={target ?? '_blank'}
+        rel="noopener noreferrer"
+        className="inline-block"
+        style={{ textDecoration: 'none' }}
+      >
+        {content}
+      </a>
+    );
+  }
+  return (
+    <Link href={href} className="inline-block" style={{ textDecoration: 'none' }}>
+      {content}
+    </Link>
+  );
+};
+
+export const GlassButton: React.FC<{
+  children: React.ReactNode;
+  href?: string;
+  external?: boolean;
+  onClick?: () => void;
+  className?: string;
+  tint?: string;
+}> = ({ children, href, external, onClick, className = '', tint }) => (
+  <GlassEffect
+    href={href}
+    external={external}
+    onClick={onClick}
+    tint={tint}
+    className={`rounded-2xl px-7 py-4 hover:px-8 ${className}`}
+  >
+    <div
+      className="transition-all duration-700 hover:scale-[0.98] whitespace-nowrap"
+      style={{ transitionTimingFunction: 'cubic-bezier(0.175, 0.885, 0.32, 2.2)' }}
+    >
+      {children}
+    </div>
+  </GlassEffect>
+);
+
+export const GlassFilter: React.FC = () => (
+  <svg style={{ display: 'none' }} aria-hidden>
+    <filter
+      id="glass-distortion"
+      x="0%"
+      y="0%"
+      width="100%"
+      height="100%"
+      filterUnits="objectBoundingBox"
+    >
+      <feTurbulence
+        type="fractalNoise"
+        baseFrequency="0.001 0.005"
+        numOctaves="1"
+        seed="17"
+        result="turbulence"
+      />
+      <feComponentTransfer in="turbulence" result="mapped">
+        <feFuncR type="gamma" amplitude="1" exponent="10" offset="0.5" />
+        <feFuncG type="gamma" amplitude="0" exponent="1" offset="0" />
+        <feFuncB type="gamma" amplitude="0" exponent="1" offset="0.5" />
+      </feComponentTransfer>
+      <feGaussianBlur in="turbulence" stdDeviation="3" result="softMap" />
+      <feSpecularLighting
+        in="softMap"
+        surfaceScale="5"
+        specularConstant="1"
+        specularExponent="100"
+        lightingColor="white"
+        result="specLight"
+      >
+        <fePointLight x="-200" y="-200" z="300" />
+      </feSpecularLighting>
+      <feComposite
+        in="specLight"
+        operator="arithmetic"
+        k1="0"
+        k2="1"
+        k3="1"
+        k4="0"
+        result="litImage"
+      />
+      <feDisplacementMap
+        in="SourceGraphic"
+        in2="softMap"
+        scale="200"
+        xChannelSelector="R"
+        yChannelSelector="G"
+      />
+    </filter>
+  </svg>
+);