feat: improve test stability and API routing

- Add proxy configuration for API requests in dev/test
- Target default endorser API server in development
- Add proxy for /api endpoints to handle CORS
- Enhance contact management test reliability
- Add comprehensive error handling and debugging
- Extract test helper functions

Breaking: None

vite.config.mjs

@@ -32,7 +32,13 @@ export default defineConfig(({ mode }) => {
       port: process.env.VITE_PORT || 8080,
       fs: {
         strict: false
-      }
+      },
+      proxy: process.env.NODE_ENV === 'development' || process.env.NODE_ENV === 'test' ? {
+        '/api': {
+          target: process.env.VITE_DEFAULT_ENDORSER_API_SERVER || 'http://localhost:3000',
+          changeOrigin: true,
+        },
+      } : undefined,
     },
     build: {
       outDir: isElectron ? "dist-electron" : "dist",