docs: clarify object ID rework descriptions and remove stale comment

Replace vague "Alpelo object system backport" references in CHANGELOG
and AUTHORS with accurate descriptions of the per-session object ID
allocation rework. Remove stale test comment referencing the deleted
NextObjectID method.

AUTHORS.md

@@ -141,7 +141,7 @@ This version focused on making the server accessible to the broader community an
 * Transmog/plate data persistence fixes
 * Logout flow improvements preventing data loss
 * Config file handling improvements
-* Alpelo object system backport
+* Object ID allocation rework (per-session IDs, stage entry notification cleanup)
 * Security updates (golang dependencies)
 
 **Technical Details:**

CHANGELOG.md

@@ -9,7 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
-- Alpelo object system backport functionality
+- Rework object ID allocation: per-session IDs replace shared map, simplify stage entry notifications
 - Better config file handling and structure
 - Comprehensive production logging for save operations (warehouse, Koryo points, savedata, Hunter Navi, plate equipment)
 - Disconnect type tracking (graceful, connection_lost, error) with detailed logging

server/channelserver/handlers_object_test.go

@@ -306,8 +306,7 @@ func TestObjectHandlers_SequentialCreateObject(t *testing.T) {
 	stage := NewStage("test_stage")
 
 	// Create objects sequentially from multiple sessions
-	// Note: handleMsgSysCreateObject has a race condition in NextObjectID
-	// so we test sequential creation instead
+	// Test sequential object creation across multiple sessions
 	for i := 0; i < 10; i++ {
 		session := createMockSession(uint32(i), server)
 		session.stage = stage