fix: enforce strict response parsing

[downfa11]

Summary

This PR aligns the Java client with the normalized Cursus response contract used by the Go and Python clients.

Changes

• Require normalized offset responses for partition consumer resume.
• Add strict protocol decoder helpers for append, snapshot, and stream version responses.
• Update event-store append/read logic to reject malformed responses.
• Add tests for strict decoder behavior and event-store response handling.

Validation

• .\gradlew.bat :cursus-client:spotlessApply :cursus-client:test