Customer Service v0.4.0 — HttpClient5 Integration + OpenAPI Cleanup

🚀 Highlights

This release introduces significant improvements to both the sample service (customer-service) and the generated client (customer-service-client).

✨ Customer Service

• Bumped project version to 0.4.0
• Updated OpenAPI configuration to fetch version directly from Maven property
• Removed hardcoded version field from OpenApiConstants
• Simplified OpenApiConfig and aligned with centralized constants
• Improved configuration properties (app.openapi.base-url)

📦 Customer Service Client

• Bumped project version to 0.4.0
• Added Apache HttpClient 5 integration with connection pooling & timeouts
• Updated CustomerApiClientConfig to support HttpClient-based RestClient
• Improved integration tests with MockWebServer
• Refined generic response wrappers (ServiceClientResponse<T>) with error details
• README updated:
  • Added build & release badges
  • Added "before vs after" wrapper comparison
  • Added HttpClient mention in feature list
  • Social preview image finalized

🔧 General

• Consistent use of ServiceClientResponse<T> naming across modules
• Cleaned up redundant constants and unused fields
• Prepared for future evolution of response envelopes with strong typing

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🔖 Tag: v0.4.0
📦 Modules: customer-service, customer-service-client
🛡 License: MIT