Update default API URL

Update the default Supabase API URL to http://a11.ism.kr.

src/contexts/auth/signInUtils.ts

@@ -16,7 +16,12 @@ export const signInWithDirectApi = async (email: string, password: string) => {
       ? supabaseUrl 
       : `${supabaseUrl}/auth/v1`;
     
-    const tokenUrl = `${baseUrl}/token?grant_type=password`;
+    // URL에 중복 '/auth/v1' 경로가 있는지 확인하고 수정
+    const normalizedUrl = baseUrl.includes('/auth/v1/auth/v1') 
+      ? baseUrl.replace('/auth/v1/auth/v1', '/auth/v1') 
+      : baseUrl;
+    
+    const tokenUrl = `${normalizedUrl}/token?grant_type=password`;
     const headers = {
       'Content-Type': 'application/json',
       'Authorization': `Bearer ${supabase.supabaseKey}`,
@@ -48,7 +53,7 @@ export const signInWithDirectApi = async (email: string, password: string) => {
       console.warn('API 경로를 찾을 수 없음 (404). 새 엔드포인트 시도 중...');
       
       // 대체 엔드포인트 시도 (/token 대신 /signin)
-      const signinUrl = `${baseUrl}/signin`;
+      const signinUrl = `${normalizedUrl}/signin`;
       
       try {
         const signinResponse = await fetch(signinUrl, {