feat: Implement user profile management and add comprehensive i18n translations for English and Thai.

Frontend-Learner/i18n/locales/en.json

@@ -118,6 +118,8 @@
   },
   "common": {
     "newBadge": "New",
-    "popularBadge": "Popular"
+    "popularBadge": "Popular",
+    "save": "Save",
+    "cancel": "Cancel"
   }
 }

Frontend-Learner/i18n/locales/th.json

@@ -118,6 +118,8 @@
   },
   "common": {
     "newBadge": "ใหม่",
-    "popularBadge": "ยอดนิยม"
+    "popularBadge": "ยอดนิยม",
+    "save": "บันทึก",
+    "cancel": "ยกเลิก"
   }
 }

Frontend-Learner/pages/dashboard/profile.vue

@@ -398,8 +398,8 @@ const saveProfile = async () => {
 
       <!-- Actions -->
       <div class="flex flex-col md:flex-row gap-4 pt-6 border-t border-white/5">
-        <button class="btn-save-premium flex-1" @click="saveProfile">{{ $t('save') }}</button>
+        <button class="btn-save-premium flex-1" @click="saveProfile">{{ $t('common.save') }}</button>
-        <button class="btn-cancel-premium md:w-32" @click="toggleEdit(false)">{{ $t('cancel') }}</button>
+        <button class="btn-cancel-premium md:w-32" @click="toggleEdit(false)">{{ $t('common.cancel') }}</button>
       </div>
     </div>
   </div>