fix(service-party-app): use API response for co-sign session status display

- Use API's participants field instead of parties
- Use API's threshold_t and threshold_n instead of activeCoSignSession
- Show participant status from API response
- Update GetSignSessionStatusResponse interface

🤖 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

@@ -1810,6 +1810,8 @@ function setupIpcHandlers() {
   ipcMain.handle('cosign:getSessionStatus', async (_event, { sessionId }) => {
     try {
       const result = await accountClient?.getSignSessionStatus(sessionId);
+      // API 返回的是 participants 字段
+      const apiParticipants = (result as { participants?: Array<{ party_id: string; party_index: number; status: string }> })?.participants || [];
       return {
         success: true,
         session: {
@@ -1817,15 +1819,15 @@ function setupIpcHandlers() {
           status: result?.status,
           joinedCount: result?.joined_count,
           threshold: {
-            t: activeCoSignSession?.threshold?.t || 0,
-            n: activeCoSignSession?.threshold?.n || 0,
+            t: result?.threshold_t || activeCoSignSession?.threshold?.t || 0,
+            n: result?.threshold_n || activeCoSignSession?.threshold?.n || 0,
           },
-          participants: result?.parties?.map((p: { party_id: string; party_index: number }, idx: number) => ({
+          participants: apiParticipants.map((p, idx) => ({
             partyId: p.party_id,
             partyIndex: p.party_index,
             name: activeCoSignSession?.participants?.find(ap => ap.partyId === p.party_id)?.name || `参与方 ${idx + 1}`,
-            status: 'ready',
-          })) || [],
+            status: p.status || 'waiting',
+          })),
           messageHash: activeCoSignSession?.messageHash || '',
           walletName: activeCoSignSession?.walletName || '',
         },

backend/mpc-system/services/service-party-app/electron/modules/account-client.ts

@@ -144,9 +144,14 @@ export interface GetSignSessionByInviteCodeResponse {
 export interface GetSignSessionStatusResponse {
   session_id: string;
   status: string;
+  session_type: string;
   threshold_t: number;
-  joined_count: number;
-  parties: SignPartyInfo[];
+  threshold_n: number;
+  completed_parties: number;
+  total_parties: number;
+  joined_count?: number;
+  parties?: SignPartyInfo[];
+  participants?: Array<{ party_id: string; party_index: number; status: string }>;
   message_hash?: string;
   signature?: string;
 }