Implement the 026-roll-initiative feature that adds d20 roll buttons for bestiary combatants' initiative using a click-to-edit pattern (d20 icon when empty, plain text when set), plus a Roll All button in the top bar that batch-rolls for all unrolled bestiary combatants, with randomness confined to the adapter layer and the domain receiving pre-resolved dice values

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

packages/application/src/roll-all-initiative-use-case.ts

@@ -0,0 +1,51 @@
+import {
+	type Creature,
+	type CreatureId,
+	calculateInitiative,
+	type DomainError,
+	type DomainEvent,
+	isDomainError,
+	rollInitiative,
+	setInitiative,
+} from "@initiative/domain";
+import type { EncounterStore } from "./ports.js";
+
+export function rollAllInitiativeUseCase(
+	store: EncounterStore,
+	rollDice: () => number,
+	getCreature: (id: CreatureId) => Creature | undefined,
+): DomainEvent[] | DomainError {
+	let encounter = store.get();
+	const allEvents: DomainEvent[] = [];
+
+	for (const combatant of encounter.combatants) {
+		if (!combatant.creatureId) continue;
+		if (combatant.initiative !== undefined) continue;
+
+		const creature = getCreature(combatant.creatureId);
+		if (!creature) continue;
+
+		const { modifier } = calculateInitiative({
+			dexScore: creature.abilities.dex,
+			cr: creature.cr,
+			initiativeProficiency: creature.initiativeProficiency,
+		});
+		const value = rollInitiative(rollDice(), modifier);
+
+		if (isDomainError(value)) {
+			return value;
+		}
+
+		const result = setInitiative(encounter, combatant.id, value);
+
+		if (isDomainError(result)) {
+			return result;
+		}
+
+		encounter = result.encounter;
+		allEvents.push(...result.events);
+	}
+
+	store.save(encounter);
+	return allEvents;
+}