feat(trading-assistant): refactor strategy creation and enhance script mode functionality

- Removed conditional rendering for the assistant guide bar.
- Simplified strategy overview and strategy list item components.
- Introduced a new modal for selecting strategy mode.
- Enhanced strategy creation modal to support script strategies with a dedicated editor.
- Updated form handling for script strategies, including validation and submission logic.
- Improved user experience with better messaging and streamlined UI components.
- Updated translations for better clarity in Chinese.

backend_api_python/app/services/llm.py

@@ -212,11 +212,11 @@ class LLMService:
             if "openrouter" in (base_url or "").lower():
                 from app.config.api_keys import APIKeys
                 if not APIKeys.OPENROUTER_API_KEY:
-                    error_msg += ". OPENROUTER_API_KEY 未配置，请在 backend_api_python/.env 中设置"
+                    error_msg += ". OPENROUTER_API_KEY is not configured. Set it in backend_api_python/.env"
                 elif response.status_code == 403:
-                    error_msg += ". 可能原因：API 密钥无效/过期、余额不足、或无模型权限。请检查 https://openrouter.ai/keys"
+                    error_msg += ". Possible causes: API key is invalid or expired, account balance is insufficient, or the model is not permitted. Check https://openrouter.ai/keys"
                 elif response.status_code == 404:
-                    error_msg += ". 可能原因：模型不可用或账户隐私/数据策略限制。请检查 https://openrouter.ai/settings/privacy"
+                    error_msg += ". Possible causes: the model is unavailable or blocked by account privacy/data-policy settings. Check https://openrouter.ai/settings/privacy"
 
             raise ValueError(error_msg)