chore(changelog): retitle v8.0.0 to highlight Decision History API + policy_version (#174)

The two user-facing surfaces this version delivers are (a) the new
listDecisions() client API + decision-history fanout to the four IDE
plugins, and (b) policy_version recorded inline on every static-policy
decision so explain stays accurate after policies are edited.

The previous title omitted the policy_version surface entirely.
Retitle aligns with the v7.9.0 platform release theme.

Signed-off-by: Saurabh Jain <saurabhjain1592@gmail.com>

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).
 
-## [8.0.0] - 2026-05-09 — Decision history API + telemetry simplification
+## [8.0.0] - 2026-05-09 — Decision History API + policy_version recorded on every decision + telemetry simplification
 
 **Major release.** The headline feature is the new decision-history client
 API: `listDecisions` for paging through recorded decisions, plus a