refactor(Loading): update Loading component import paths

- Changed import paths for the Loading component from "@/app/loading" to "@/components/loading" across multiple files to maintain consistency and improve modularity.
- Removed the Loading component definition from loading.tsx, simplifying the file structure.

src/contexts/Auth-guard.ctx.tsx

@@ -3,7 +3,7 @@
 import { useRouter } from "next/navigation";
 import { useEffect, ReactNode } from "react";
 import { useUser } from "./";
-import Loading from "@/app/loading";
+import Loading from "@/components/loading";
 
 interface AuthGuardProps {
   children: ReactNode;
@@ -20,7 +20,7 @@ const AuthGuard = ({ children }: AuthGuardProps): React.ReactNode => {
   }, [isLoading, isAuthenticated, router]);
 
   if (isLoading || !isAuthenticated) {
-    return <Loading />;
+    return <Loading className="min-h-svh flex-none" />;
   }
 
   return children;