Implement the 002-add-combatant feature that adds the possibility to add new combatants to an encounter

apps/web/src/hooks/use-encounter.ts

@@ -1,5 +1,8 @@
 import type { EncounterStore } from "@initiative/application";
-import { advanceTurnUseCase } from "@initiative/application";
+import {
+	addCombatantUseCase,
+	advanceTurnUseCase,
+} from "@initiative/application";
 import type { DomainEvent, Encounter } from "@initiative/domain";
 import {
 	combatantId,
@@ -28,20 +31,38 @@ export function useEncounter() {
 	const encounterRef = useRef(encounter);
 	encounterRef.current = encounter;
 
-	const advanceTurn = useCallback(() => {
-		const store: EncounterStore = {
+	const makeStore = useCallback((): EncounterStore => {
+		return {
 			get: () => encounterRef.current,
 			save: (e) => setEncounter(e),
 		};
+	}, []);
 
-		const result = advanceTurnUseCase(store);
+	const advanceTurn = useCallback(() => {
+		const result = advanceTurnUseCase(makeStore());
 
 		if (isDomainError(result)) {
 			return;
 		}
 
 		setEvents((prev) => [...prev, ...result]);
-	}, []);
+	}, [makeStore]);
 
-	return { encounter, events, advanceTurn } as const;
+	const nextId = useRef(0);
+
+	const addCombatant = useCallback(
+		(name: string) => {
+			const id = combatantId(`c-${++nextId.current}`);
+			const result = addCombatantUseCase(makeStore(), id, name);
+
+			if (isDomainError(result)) {
+				return;
+			}
+
+			setEvents((prev) => [...prev, ...result]);
+		},
+		[makeStore],
+	);
+
+	return { encounter, events, advanceTurn, addCombatant } as const;
 }