Refactor: Split Sidebar.tsx into smaller components

Refactored the Sidebar component into smaller, more manageable files to improve code organization and maintainability.

Fix sidebar auto-expansion issue
Ensured the sidebar's collapsed state is maintained when navigating between pages.

application/src/components/dashboard/sidebar/SidebarHeader.tsx

@@ -0,0 +1,20 @@
+
+import React from "react";
+import { useTheme } from "@/contexts/ThemeContext";
+
+interface SidebarHeaderProps {
+  collapsed: boolean;
+}
+
+export const SidebarHeader: React.FC<SidebarHeaderProps> = ({ collapsed }) => {
+  const { theme } = useTheme();
+
+  return (
+    <div className={`p-4 ${theme === 'dark' ? 'border-[#1e1e1e]' : 'border-sidebar-border'} border-b flex items-center ${collapsed ? 'justify-center' : ''}`}>
+      <div className="h-8 w-8 bg-green-500 rounded flex items-center justify-center mr-2">
+        <span className="text-white font-bold">C</span>
+      </div>
+      {!collapsed && <h1 className="text-xl font-semibold">CheckCle App</h1>}
+    </div>
+  );
+};