account_api 抽出 error_field 消除 message/code 的重复解析

error_message / error_code 只差字段名，合并到 error_field(body, field)
调用点保留 error_message / error_code 两个薄封装

apps/ai-game-creator-shell/src-tauri/src/account_api.rs

@@ -67,26 +67,23 @@ fn bounded_business_id(value: &str, label: &str) -> Result<String, String> {
     Ok(value.to_string())
 }
 
-fn error_message(body: &str) -> Option<String> {
+fn error_field(body: &str, field: &str) -> Option<String> {
     let value = serde_json::from_str::<Value>(body).ok()?;
     let error = value.get("error").unwrap_or(&value);
     error
-        .get("message")
+        .get(field)
         .and_then(Value::as_str)
         .map(str::trim)
-        .filter(|message| !message.is_empty())
+        .filter(|detail| !detail.is_empty())
         .map(ToString::to_string)
 }
 
+fn error_message(body: &str) -> Option<String> {
+    error_field(body, "message")
+}
+
 fn error_code(body: &str) -> Option<String> {
-    let value = serde_json::from_str::<Value>(body).ok()?;
-    let error = value.get("error").unwrap_or(&value);
-    error
-        .get("code")
-        .and_then(Value::as_str)
-        .map(str::trim)
-        .filter(|code| !code.is_empty())
-        .map(ToString::to_string)
+    error_field(body, "code")
 }
 
 fn map_http_error(status: StatusCode, body: &str, fallback: &str) -> String {