The query_siliconflow function received an is_cn flag that only switched
the request domain (.cn vs .com) but the response builder hardcoded
unit="CNY" for both sites. International users at api.siliconflow.com
saw their USD balance labelled as CNY. Now unit and plan_name follow
is_cn, so the EN site shows USD and "SiliconFlow (EN)".
Add a new "Official" (官方) template type in the usage query panel that
queries account balance via each provider's native API endpoint.
Follows the same zero-script pattern as Token Plan — Rust handles the
HTTP call, frontend auto-detects the provider from base URL.
Supported providers and endpoints:
- DeepSeek: GET /user/balance
- StepFun: GET /v1/accounts
- SiliconFlow: GET /v1/user/info (cn + com)
- OpenRouter: GET /api/v1/credits
- Novita AI: GET /v3/user/balance
Jason