Add shader gradient background with halo effect

- Installed @shadergradient/react, three, and @types/three
- Created ShaderGradientBackground component with custom gradient settings
- Integrated background into root layout with blur effect (120px) and reduced opacity (0.5)
- Adjusted body background to work harmoniously with shader gradient
- Used sphere type with pink/orange gradient colors (#b01040, #b04a17, #e167c5)
- Configured animation, grain, and lighting for atmospheric effect

app/globals.css

@@ -27,7 +27,7 @@
 }
 
 body {
-    background-color: var(--background);
+    background: linear-gradient(135deg, rgba(250, 248, 243, 0.95) 0%, rgba(250, 248, 243, 0.92) 100%);
     color: var(--foreground);
     font-family: "Inter", sans-serif;
     margin: 0;
@@ -36,6 +36,7 @@ body {
     -webkit-font-smoothing: antialiased;
     -moz-osx-font-smoothing: grayscale;
     text-rendering: optimizeLegibility;
+    position: relative;
 }
 
 /* Custom Selection */