Enhance image upload and background management: Update Docker configuration to create a dedicated backgrounds directory for uploaded images, modify API routes to handle background images specifically, and improve README documentation to reflect these changes. Additionally, refactor components to utilize the new Avatar component for consistent avatar rendering across the application.

components/ProfileForm.tsx

@@ -1,6 +1,7 @@
 "use client";
 
 import { useState, useRef, type ChangeEvent } from "react";
+import Avatar from "./Avatar";
 
 type CharacterClass =
   | "WARRIOR"
@@ -242,19 +243,12 @@ export default function ProfileForm({
             {/* Avatar Section */}
             <div className="flex flex-col items-center gap-4">
               <div className="relative">
-                <div className="w-32 h-32 rounded-full border-4 border-pixel-gold/50 overflow-hidden bg-gray-900 flex items-center justify-center">
-                  {avatar ? (
-                    <img
-                      src={avatar}
-                      alt={username}
-                      className="w-full h-full object-cover"
-                    />
-                  ) : (
-                    <span className="text-pixel-gold text-4xl font-bold">
-                      {username.charAt(0).toUpperCase()}
-                    </span>
-                  )}
-                </div>
+                <Avatar
+                  src={avatar}
+                  username={username}
+                  size="2xl"
+                  borderClassName="border-4 border-pixel-gold/50"
+                />
                 {uploadingAvatar && (
                   <div className="absolute inset-0 bg-black/60 flex items-center justify-center rounded-full">
                     <div className="text-pixel-gold text-sm">Upload...</div>