fix(service-party-app): 修复Kava API健康检查逻辑

问题: Kava API检测失败，原因是使用测试地址查询余额的方式不可靠

解决方案:
1. 添加 healthCheck() 方法到 KavaTxService，查询最新区块
2. 添加 kava:healthCheck IPC 处理器
3. 更新 appStore 使用 healthCheck API 而非 getBalance

修改的文件:
- kava-tx-service.ts: 添加 healthCheck() 方法
- main.ts: 添加 kava:healthCheck IPC 处理器
- preload.ts: 暴露 healthCheck API
- appStore.ts: 使用 healthCheck 检测 Kava API
- electron.d.ts: 添加 KavaHealthCheckResult 类型

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/mpc-system/services/service-party-app/electron/main.ts

@@ -536,6 +536,16 @@ function setupIpcHandlers() {
     }
   });
 
+  // Kava 健康检查
+  ipcMain.handle('kava:healthCheck', async () => {
+    try {
+      const result = await kavaTxService?.healthCheck();
+      return { success: result?.ok ?? false, data: result };
+    } catch (error) {
+      return { success: false, error: (error as Error).message };
+    }
+  });
+
   // ===========================================================================
   // 对话框相关
   // ===========================================================================

backend/mpc-system/services/service-party-app/electron/modules/kava-tx-service.ts

@@ -500,6 +500,43 @@ export class KavaTxService {
   disconnect(): void {
     // REST API 无需断开连接
   }
+
+  /**
+   * 健康检查 - 验证 API 是否可用
+   */
+  async healthCheck(): Promise<{ ok: boolean; latency?: number; error?: string }> {
+    const startTime = Date.now();
+    try {
+      // 查询链的最新区块，这是最轻量级的检查
+      const response = await this.request<{
+        block: {
+          header: {
+            height: string;
+            chain_id: string;
+          };
+        };
+      }>('/cosmos/base/tendermint/v1beta1/blocks/latest');
+
+      const latency = Date.now() - startTime;
+
+      if (response?.block?.header?.height) {
+        return {
+          ok: true,
+          latency,
+        };
+      }
+
+      return {
+        ok: false,
+        error: 'Invalid response format',
+      };
+    } catch (error) {
+      return {
+        ok: false,
+        error: error instanceof Error ? error.message : String(error),
+      };
+    }
+  }
 }
 
 // 导出默认服务实例

backend/mpc-system/services/service-party-app/electron/preload.ts

@@ -182,6 +182,9 @@ contextBridge.exposeInMainWorld('electronAPI', {
       rpcEndpoint?: string;
       chainId?: string;
     }) => ipcRenderer.invoke('kava:updateConfig', { config }),
+
+    // 健康检查
+    healthCheck: () => ipcRenderer.invoke('kava:healthCheck'),
   },
 
   // ===========================================================================

backend/mpc-system/services/service-party-app/src/stores/appStore.ts

@@ -139,21 +139,20 @@ export const useAppStore = create<AppState>((set, get) => ({
     setKavaApiStatus({ status: 'checking', message: '正在检测...' });
     try {
       if (window.electronAPI) {
-        // 使用一个已知的测试地址查询余额来验证 API
-        const testAddress = 'kava1qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqnxwpql';
-        const result = await window.electronAPI.kava.getBalance(testAddress);
-        if (result.success || result.error?.includes('account')) {
-          // 即使账户不存在，API 能响应也说明连接正常
+        // 使用健康检查 API (查询最新区块)
+        const result = await window.electronAPI.kava.healthCheck();
+        if (result.success && result.data?.ok) {
           const config = await window.electronAPI.kava.getConfig();
+          const latencyMsg = result.data.latency ? ` (${result.data.latency}ms)` : '';
           setKavaApiStatus({
             status: 'connected',
-            message: config?.lcdEndpoint || 'Kava Mainnet',
+            message: (config?.lcdEndpoint || 'Kava Mainnet') + latencyMsg,
             lastChecked: new Date(),
           });
         } else {
           setKavaApiStatus({
             status: 'error',
-            message: result.error || 'API 响应异常',
+            message: result.data?.error || result.error || 'API 响应异常',
             lastChecked: new Date(),
           });
         }

backend/mpc-system/services/service-party-app/src/types/electron.d.ts

@@ -331,6 +331,16 @@ interface GetKavaTxStatusResult {
   error?: string;
 }
 
+interface KavaHealthCheckResult {
+  success: boolean;
+  data?: {
+    ok: boolean;
+    latency?: number;
+    error?: string;
+  };
+  error?: string;
+}
+
 // ===========================================================================
 // Electron API 接口
 // ===========================================================================
@@ -403,6 +413,7 @@ interface ElectronAPI {
     getTxStatus: (txHash: string) => Promise<GetKavaTxStatusResult>;
     getConfig: () => Promise<KavaConfig>;
     updateConfig: (config: Partial<KavaConfig>) => Promise<{ success: boolean; error?: string }>;
+    healthCheck: () => Promise<KavaHealthCheckResult>;
   };
 
   // 对话框相关