fix(mobile): leave login usernames blank

Refs #74

apps/ios/EdgeEver/Features/Auth/LoginView.swift

@@ -4,7 +4,7 @@ import Pow
 struct LoginView: View {
     @Environment(AppEnvironment.self) private var env
     @State private var baseUrl = ""
-    @State private var username = "admin"
+    @State private var username = ""
     @State private var password = ""
     @State private var error: String?
     @State private var submitting = false
@@ -75,7 +75,7 @@ struct LoginView: View {
 
                     field(
                         env.preferences.t("用户名", en: "Username", ja: "ユーザー名"),
-                        placeholder: "owner",
+                        placeholder: "",
                         text: $username,
                         keyboard: .default,
                         secure: false

apps/mobile/src/screens/LoginScreen.tsx

@@ -24,7 +24,7 @@ export const LoginScreen = () => {
   refreshLoginThemeStyles(resolvedTheme);
   const { signIn } = useSession();
   const [baseUrl, setBaseUrl] = useState("");
-  const [username, setUsername] = useState("admin");
+  const [username, setUsername] = useState("");
   const [password, setPassword] = useState("");
   const [error, setError] = useState<string | null>(null);
   const [submitting, setSubmitting] = useState(false);
@@ -89,8 +89,6 @@ export const LoginScreen = () => {
                 autoCapitalize="none"
                 autoCorrect={false}
                 onChangeText={setUsername}
-                placeholder="owner"
-                placeholderTextColor="#94a3b8"
                 style={styles.input}
                 value={username}
               />