fix(frontend): remove Email label

- Replace "Email" with "Login Id" for consistency with SignUp.tsx

Author: Genyus

frontend/src/pages/SignIn.tsx

@@ -10,7 +10,7 @@ import { authenticate, getUserByLogin } from "../utils/api";
 import SignUp from './SignUp';
 
 const SignIn = () => {
-    const [email, setEmail] = useState<string>('');
+    const [loginId, setLoginId] = useState<string>('');
     const [password, setPassword] = useState<string>('');
     const navigate = useNavigate();
     const [isSnackBarOpen, setIsSnackBarOpen] = React.useState(false);
@@ -22,11 +22,11 @@ const SignIn = () => {
         setLoading(true)
         e.preventDefault();
         try {
-            const authRes = await authenticate(email, password);
+            const authRes = await authenticate(loginId, password);
             if (authRes.status === 200) {
                 localStorage.setItem("authenticated", "true");
                 sessionStorage.setItem("authenticated", "true")
-                const userRes = await getUserByLogin(email);
+                const userRes = await getUserByLogin(loginId);
                 if (userRes.status === 200) {
                     const user = userRes.data;
                     userStore.user = user;
@@ -70,14 +70,14 @@ const SignIn = () => {
                          src={avatar} alt="avatar"/>
                     <Input
                         type="userid"
-                        name="email"
-                        label="Email"
+                        name="loginId"
+                        label="Login Id"
                         required
                         variant="primary"
                         size="md"
                         autoComplete="username"
-                        value={email}
-                        onChange={e => setEmail(e.target.value)}
+                        value={loginId}
+                        onChange={e => setLoginId(e.target.value)}
                     />
                     <Input
                         type="password"