[FIX] 修復個人檔案與導覽列頭像不顯示問題，並實作即時更新邏輯

app/Models/System/User.php

@@ -82,4 +82,17 @@ class User extends Authenticatable
     {
         return !is_null($this->company_id);
     }
+
+    /**
+     * Get the URL for the user's avatar.
+     */
+    public function getAvatarUrlAttribute(): string
+    {
+        if ($this->avatar) {
+            return \Illuminate\Support\Facades\Storage::disk('public')->url($this->avatar);
+        }
+
+        // Return a default UI Avatar if no avatar is set
+        return "https://ui-avatars.com/api/?name=" . urlencode($this->name) . "&color=7F9CF5&background=EBF4FF";
+    }
 }