fix: 订阅模式登录验证、永久会员类型区分、动态代码HTTP返回值修复、侧边栏滚动位置保持

- 修复订阅模式登录时错误检查余额的问题
- 区分无限余额和永久订阅两种永久会员类型
- 修复动态代码HTTP请求返回值在JS中无法正确访问的问题
- 添加侧边栏滚动位置保持功能
- 移除developer角色相关代码，统一使用admin
- 添加缺失的i18n翻译key

backend/scripts/translate_docs_i18n.go

@@ -1,4 +1,4 @@
-package main
+package main
 
 import (
 	"fmt"
@@ -145,7 +145,7 @@ func main() {
 		},
 		"如何获取API密钥？": {
 			TitleEn:   "How to Get API Key?",
-			ContentEn: "# How to Get API Key?\n\n## Steps\n\n### 1. Register Account\nFirst, register a developer account on the platform.\n\n### 2. Create Application\n1. Go to Console > Applications\n2. Click \"Create Application\" button\n3. Fill in application name and description\n4. Click \"Create\"\n\n### 3. Get App Key\nAfter creating the application, you can find the App Key on the application details page.\n\n## App Key Format\nApp Key is a unique identifier in the format:\n```\napp_xxxxxxxxxxxxxxxx\n```\n\n## Security Notes\n- Do not share your App Key publicly\n- Regenerate App Key if it's compromised\n- Use environment variables to store App Key in production",
+			ContentEn: "# How to Get API Key?\n\n## Steps\n\n### 1. Register Account\nFirst, register a admin account on the platform.\n\n### 2. Create Application\n1. Go to Console > Applications\n2. Click \"Create Application\" button\n3. Fill in application name and description\n4. Click \"Create\"\n\n### 3. Get App Key\nAfter creating the application, you can find the App Key on the application details page.\n\n## App Key Format\nApp Key is a unique identifier in the format:\n```\napp_xxxxxxxxxxxxxxxx\n```\n\n## Security Notes\n- Do not share your App Key publicly\n- Regenerate App Key if it's compromised\n- Use environment variables to store App Key in production",
 		},
 		"卡密验证失败怎么办？": {
 			TitleEn:   "What to Do When Card Key Verification Fails?",