feat(character-banner): 배너 등록 언어 선택 추가

- 배너 등록/수정 다이얼로그에 언어 선택(ko/ja/en) UI를 추가

src/views/Chat/CharacterBanner.vue

@@ -184,6 +184,19 @@
                 </v-alert>
               </v-col>
             </v-row>
+            <v-row>
+              <v-col cols="12">
+                <v-select
+                  v-model="bannerForm.lang"
+                  :items="languageOptions"
+                  label="언어 선택"
+                  item-text="text"
+                  item-value="value"
+                  :disabled="isEdit"
+                  outlined
+                />
+              </v-col>
+            </v-row>
             <v-row v-if="selectedCharacter">
               <v-col cols="12">
                 <v-alert
@@ -302,8 +315,14 @@ export default {
         image: null,
         imageUrl: '',
         characterId: null,
-        bannerId: null
+        bannerId: null,
+        lang: null
       },
+      languageOptions: [
+        { text: '한국어', value: 'ko' },
+        { text: '일본어', value: 'ja' },
+        { text: '영어', value: 'en' }
+      ],
       imageRules: [
         v => !!v || this.isEdit || '이미지를 선택하세요'
       ]
@@ -312,7 +331,7 @@ export default {
 
   computed: {
     isFormValid() {
-      return (this.bannerForm.image || (this.isEdit && this.bannerForm.imageUrl)) && this.selectedCharacter;
+      return (this.bannerForm.image || (this.isEdit && this.bannerForm.imageUrl)) && this.selectedCharacter && this.bannerForm.lang;
     }
   },
 
@@ -393,7 +412,8 @@ export default {
         image: null,
         imageUrl: '',
         characterId: null,
-        bannerId: null
+        bannerId: null,
+        lang: null
       };
       this.previewImage = null;
       this.searchKeyword = '';
@@ -414,7 +434,8 @@ export default {
         image: null,
         imageUrl: banner.imageUrl,
         characterId: banner.characterId,
-        bannerId: banner.id
+        bannerId: banner.id,
+        lang: banner.lang || banner.language || null
       };
       this.previewImage = null;
       this.searchKeyword = '';
@@ -430,7 +451,8 @@ export default {
         image: null,
         imageUrl: '',
         characterId: null,
-        bannerId: null
+        bannerId: null,
+        lang: null
       };
       this.previewImage = null;
       this.searchKeyword = '';
@@ -501,7 +523,8 @@ export default {
           // 배너 추가
           const response = await createCharacterBanner({
             image: this.bannerForm.image,
-            characterId: this.selectedCharacter.id
+            characterId: this.selectedCharacter.id,
+            lang: this.bannerForm.lang
           });
           if (response && response.status === 200 && response.data && response.data.success === true) {
             this.notifySuccess('배너가 추가되었습니다.');