Implement the 003-remove-combatant feature that adds the possibility to remove a combatant from an encounter

packages/application/src/index.ts

@@ -1,3 +1,4 @@
 export { addCombatantUseCase } from "./add-combatant-use-case.js";
 export { advanceTurnUseCase } from "./advance-turn-use-case.js";
 export type { EncounterStore } from "./ports.js";
+export { removeCombatantUseCase } from "./remove-combatant-use-case.js";

packages/application/src/remove-combatant-use-case.ts

@@ -0,0 +1,23 @@
+import {
+	type CombatantId,
+	type DomainError,
+	type DomainEvent,
+	isDomainError,
+	removeCombatant,
+} from "@initiative/domain";
+import type { EncounterStore } from "./ports.js";
+
+export function removeCombatantUseCase(
+	store: EncounterStore,
+	id: CombatantId,
+): DomainEvent[] | DomainError {
+	const encounter = store.get();
+	const result = removeCombatant(encounter, id);
+
+	if (isDomainError(result)) {
+		return result;
+	}
+
+	store.save(result.encounter);
+	return result.events;
+}