diff --git a/CHANGELOG.md b/CHANGELOG.md
index 98f1e39b1..ddc970d54 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,11 @@ Format based on [Keep a Changelog](https://keepachangelog.com/).
 ## [Unreleased]
 
 ### Added
+- Observer visibility query (#112) — replaces unfiltered generate_snapshot with LOS-filtered compute_observer_snapshot combining shadowcasting + vision cone
+- Vision cone system (#111) — forward/peripheral/blind sectors per D-015, Facing component updated on movement
+- Symmetric shadowcasting (#110, #359) — Albert Ford algorithm with rational fraction slopes, benchmarked 1.2-10.5x faster than recursive, symmetry guaranteed (D-035)
+- ObserverSnapshot v2 schema (#358, #25) — version field, GameTime, FacingDirection, VisibleTile, VisibilitySector types, visibility tag on entities
+- D-035 decision record — symmetric shadowcasting selected over recursive (resolves Q-018)
 - `ticket team` command and `--team` filter — comma-separated team assignment for tickets (server, client, joint, content)
 
 ### Fixed
@@ -153,6 +158,7 @@ Format based on [Keep a Changelog](https://keepachangelog.com/).
 - dotfiles/tmux.conf (no longer needed)
 
 ### Changed
+- Q-018 (shadowcasting algorithm selection) resolved via D-035
 - All 18 agent briefings updated for decisions/ directory split and DEVOPS.md references
 - Implementation agents (Dudley, Hoshe, Justine, Oscar, Si, Stig, Tyre) now include Development Workflow sections with Makefile targets
 - Q-009 (time system) resolved via D-031