fix(service-party-app): 修复 electron-builder files 配置

- 将 electron/**/* 改为 dist-electron/**/* (编译后的文件)
- 添加 proto/**/* (gRPC proto 文件)

🤖 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/package.json

@@ -54,8 +54,9 @@
     },
     "files": [
       "dist/**/*",
-      "electron/**/*",
+      "dist-electron/**/*",
-      "wasm/**/*"
+      "wasm/**/*",
+      "proto/**/*"
     ],
     "win": {
       "target": [