Implement the 005-set-initiative feature that adds initiative values to combatants with automatic descending sort and active turn preservation

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

packages/domain/src/events.ts

@@ -32,9 +32,17 @@ export interface CombatantUpdated {
 	readonly newName: string;
 }
 
+export interface InitiativeSet {
+	readonly type: "InitiativeSet";
+	readonly combatantId: CombatantId;
+	readonly previousValue: number | undefined;
+	readonly newValue: number | undefined;
+}
+
 export type DomainEvent =
 	| TurnAdvanced
 	| RoundAdvanced
 	| CombatantAdded
 	| CombatantRemoved
-	| CombatantUpdated;
+	| CombatantUpdated
+	| InitiativeSet;