Merge pull request #2: feat(simulation): add Rust/bevy_ecs server boilerplate

Merge origin/server into main. Resolve CHANGELOG.md conflict by keeping
both sets of entries (main's review-pr skill + server's boilerplate entries).

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

Makefile

@@ -74,7 +74,7 @@ client:
 test: test-server test-client
 
 test-server:
-	cd server && cargo test
+	cd server && cargo nextest run
 
 test-client:
 	@echo "Client tests run via gdUnit4 inside Godot."