feat: add official balance query for DeepSeek, StepFun, SiliconFlow, OpenRouter, Novita AI

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

src-tauri/src/commands/provider.rs

@@ -14,6 +14,7 @@ use std::str::FromStr;
 // 常量定义
 const TEMPLATE_TYPE_GITHUB_COPILOT: &str = "github_copilot";
 const TEMPLATE_TYPE_TOKEN_PLAN: &str = "token_plan";
+const TEMPLATE_TYPE_BALANCE: &str = "balance";
 const COPILOT_UNIT_PREMIUM: &str = "requests";
 
 /// 获取所有供应商
@@ -268,6 +269,30 @@ pub async fn queryProviderUsage(
         });
     }
 
+    // ── 官方余额查询路径 ──
+    if template_type == TEMPLATE_TYPE_BALANCE {
+        let settings_config = provider
+            .map(|p| &p.settings_config)
+            .cloned()
+            .unwrap_or_default();
+        let env = settings_config.get("env");
+        let base_url = env
+            .and_then(|e| e.get("ANTHROPIC_BASE_URL"))
+            .and_then(|v| v.as_str())
+            .unwrap_or("");
+        let api_key = env
+            .and_then(|e| {
+                e.get("ANTHROPIC_AUTH_TOKEN")
+                    .or_else(|| e.get("ANTHROPIC_API_KEY"))
+            })
+            .and_then(|v| v.as_str())
+            .unwrap_or("");
+
+        return crate::services::balance::get_balance(base_url, api_key)
+            .await
+            .map_err(|e| format!("Failed to query balance: {e}"));
+    }
+
     // ── 通用 JS 脚本路径 ──
     ProviderService::query_usage(state.inner(), app_type, &providerId)
         .await