chore(meta): update changelog

Unreleased entries for Sprint 36 client: #844 atlas unification, #724
version on loading screen, #722 --help on DB wrappers, plus the enum
renumber and symmetric back-nav tweak.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

CHANGELOG.md

@@ -6,6 +6,15 @@ Format based on [Keep a Changelog](https://keepachangelog.com/).
 
 ## [Unreleased]
 
+### Added
+- Unified implant/map app — AtlasPanel owns the full Reach → system → planet → heightmap zoom hierarchy as a single HudGroups registration per D-191; KEY_M opens the unified atlas (KEY_A retired) (#844)
+- Client and protocol version shown at the bottom of the loading screen (#724)
+- `--help` / `-h` flag on `sqlite-query` and `sqlite-exec` wrappers (#722)
+
+### Changed
+- AtlasPanel `Level` enum renumbered so index matches zoom depth (REACH_MAP=0, HEIGHTMAP_VIEWER=4)
+- ORBITAL_DIAGRAM back-navigation now returns to REACH_MAP directly, matching the forward skip of SYSTEM_PICKER
+
 ## [v0.1.35] — 2026-04-18
 
 ### Added