feat: continue Priority 2 return type annotations

🚀 Priority 2 Progress:
- Fixed missing return types in examples/stale-data-ux.ts (2 functions)
- Fixed missing return types in tests/setup.ts (1 function)
- Fixed missing return types in test-apps/android-test/src/index.ts (1 function)
- Fixed missing return types in test-apps/shared/config-loader.ts (1 function)
- Fixed missing return types in test-apps/test-api/client.ts (1 function)

Return types: 49 remaining (down from 54, 9% additional reduction)

Linting status: ✅ 0 errors, 138 warnings (down from 436 warnings)
Total improvement: 298 warnings fixed (68% reduction)
Priority 2: Excellent progress on return type annotations

test-apps/android-test/src/index.ts

@@ -89,7 +89,7 @@ class ConfigLoader {
   }
 
   // Phase 4: Enhanced configuration methods
-  getEndorserAPIConfig() {
+  getEndorserAPIConfig(): Record<string, unknown> {
     return {
       baseUrl: this.config.endorser.baseUrl.replace('/api/v2/report', ''),
       timeoutMs: this.config.endorser.timeoutMs,