docs: add BudgetInfo to changelog (#62)

Author: saurabhjain1592

CHANGELOG.md

@@ -5,7 +5,7 @@ All notable changes to the AxonFlow Java SDK will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [2.7.0] - 2026-01-24
+## [2.7.0] - 2026-01-25
 
 ### Added
 
@@ -36,6 +36,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   - Documents when to use Proxy Mode vs Gateway Mode
   - Both sync (`proxyLLMCall`) and async (`proxyLLMCallAsync`) variants
 
+- **BudgetInfo**: `QueryResponse.getBudgetInfo()` for budget enforcement (HTTP 402)
+
 ### Deprecated
 
 - **executeQuery()**: Deprecated in favor of proxyLLMCall()