style(ui): adjust header spacing and remove unused imports

Remove unused lucide-react icons (FileText, Folder) and cn utility import.
Add responsive padding to header elements for better mobile layout.

app/components/header.tsx

@@ -15,9 +15,8 @@ import {
 } from "@/components/ui/navigation-menu";
 import { Button } from "@/components/ui/button";
 import { Sheet, SheetContent, SheetTrigger } from "@/components/ui/sheet";
-import { Menu, FileText, Home, Folder, Settings, User, LogOut, LogIn } from "lucide-react";
+import { Menu, Home, Settings, User, LogOut, LogIn } from "lucide-react";
 import { DarkModeToggle } from "./dark-mode-toggle";
-import { cn } from "@/lib/utils";
 import React from "react";
 
 const userMenuItems = [
@@ -46,7 +45,7 @@ export default function Header() {
     return (
       <header className="sticky top-0 z-50 w-full border-b bg-background/95 backdrop-blur supports-[backdrop-filter]:bg-background/60">
         <div className="container flex h-16 items-center justify-between">
-          <div className="flex items-center gap-6">
+          <div className="flex items-center gap-6 pl-4 md:pl-6">
             <Link href="/" className="flex items-center space-x-2">
               <Image
                 src={logoSrc}
@@ -58,7 +57,7 @@ export default function Header() {
               />
             </Link>
           </div>
-          <div className="flex items-center gap-4">
+          <div className="flex items-center gap-4 pr-4 md:pr-6">
             <div className="h-8 w-20 bg-gray-200 animate-pulse rounded"></div>
           </div>
         </div>
@@ -69,7 +68,7 @@ export default function Header() {
   return (
     <header className="sticky top-0 z-50 w-full border-b bg-background/95 backdrop-blur supports-[backdrop-filter]:bg-background/60">
       <div className="container flex h-16 items-center justify-between">
-        <div className="flex items-center gap-6">
+        <div className="flex items-center gap-6 pl-4 md:pl-6">
           <Link href="/" className="flex items-center space-x-2">
             <Image
               src={logoSrc}
@@ -82,7 +81,7 @@ export default function Header() {
           </Link>
         </div>
 
-        <div className="flex items-center gap-4">
+        <div className="flex items-center gap-4 pr-4 md:pr-6">
           <DarkModeToggle />
           
           {isAuthenticated ? (