Add Pathfinder 2e game system mode

Implements PF2e as an alternative game system alongside D&D 5e/5.5e.
Settings modal "Game System" selector switches conditions, bestiary,
stat block layout, and initiative calculation between systems.

- Valued conditions with increment/decrement UX (Clumsy 2, Frightened 3)
- 2,502 PF2e creatures from bundled search index (77 sources)
- PF2e stat block: level, traits, Perception, Fort/Ref/Will, ability mods
- Perception-based initiative rolling
- System-scoped source cache (D&D and PF2e sources don't collide)
- Backwards-compatible condition rehydration (ConditionId[] → ConditionEntry[])
- Difficulty indicator hidden in PF2e mode (excluded from MVP)

Closes dostulata/initiative#19

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/application/src/__tests__/use-cases.test.ts

@@ -292,9 +292,9 @@ describe("toggleConditionUseCase", () => {
 		);
 
 		expect(isDomainError(result)).toBe(false);
-		expect(requireSaved(store.saved).combatants[0].conditions).toContain(
-			"blinded",
-		);
+		expect(requireSaved(store.saved).combatants[0].conditions).toContainEqual({
+			id: "blinded",
+		});
 	});
 
 	it("returns domain error for unknown combatant", () => {

packages/application/src/creature-initiative-modifier.ts

@@ -0,0 +1,21 @@
+import {
+	type AnyCreature,
+	calculateInitiative,
+	calculatePf2eInitiative,
+} from "@initiative/domain";
+
+export function creatureInitiativeModifier(creature: AnyCreature): number {
+	if ("system" in creature && creature.system === "pf2e") {
+		return calculatePf2eInitiative(creature.perception).modifier;
+	}
+	const c = creature as {
+		abilities: { dex: number };
+		cr: string;
+		initiativeProficiency: number;
+	};
+	return calculateInitiative({
+		dexScore: c.abilities.dex,
+		cr: c.cr,
+		initiativeProficiency: c.initiativeProficiency,
+	}).modifier;
+}

packages/application/src/decrement-condition-use-case.ts

@@ -0,0 +1,19 @@
+import {
+	type CombatantId,
+	type ConditionId,
+	type DomainError,
+	type DomainEvent,
+	decrementCondition,
+} from "@initiative/domain";
+import type { EncounterStore } from "./ports.js";
+import { runEncounterAction } from "./run-encounter-action.js";
+
+export function decrementConditionUseCase(
+	store: EncounterStore,
+	combatantId: CombatantId,
+	conditionId: ConditionId,
+): DomainEvent[] | DomainError {
+	return runEncounterAction(store, (encounter) =>
+		decrementCondition(encounter, combatantId, conditionId),
+	);
+}

packages/application/src/index.ts

@@ -3,6 +3,7 @@ export { adjustHpUseCase } from "./adjust-hp-use-case.js";
 export { advanceTurnUseCase } from "./advance-turn-use-case.js";
 export { clearEncounterUseCase } from "./clear-encounter-use-case.js";
 export { createPlayerCharacterUseCase } from "./create-player-character-use-case.js";
+export { decrementConditionUseCase } from "./decrement-condition-use-case.js";
 export { deletePlayerCharacterUseCase } from "./delete-player-character-use-case.js";
 export { editCombatantUseCase } from "./edit-combatant-use-case.js";
 export { editPlayerCharacterUseCase } from "./edit-player-character-use-case.js";
@@ -21,6 +22,7 @@ export {
 } from "./roll-all-initiative-use-case.js";
 export { rollInitiativeUseCase } from "./roll-initiative-use-case.js";
 export { setAcUseCase } from "./set-ac-use-case.js";
+export { setConditionValueUseCase } from "./set-condition-value-use-case.js";
 export { setCrUseCase } from "./set-cr-use-case.js";
 export { setHpUseCase } from "./set-hp-use-case.js";
 export { setInitiativeUseCase } from "./set-initiative-use-case.js";

packages/application/src/ports.ts

@@ -1,5 +1,5 @@
 import type {
-	Creature,
+	AnyCreature,
 	CreatureId,
 	Encounter,
 	PlayerCharacter,
@@ -12,7 +12,7 @@ export interface EncounterStore {
 }
 
 export interface BestiarySourceCache {
-	getCreature(creatureId: CreatureId): Creature | undefined;
+	getCreature(creatureId: CreatureId): AnyCreature | undefined;
 	isSourceCached(sourceCode: string): boolean;
 }
 

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

@@ -1,7 +1,6 @@
 import {
-	type Creature,
+	type AnyCreature,
 	type CreatureId,
-	calculateInitiative,
 	type DomainError,
 	type DomainEvent,
 	isDomainError,
@@ -10,6 +9,7 @@ import {
 	selectRoll,
 	setInitiative,
 } from "@initiative/domain";
+import { creatureInitiativeModifier } from "./creature-initiative-modifier.js";
 import type { EncounterStore } from "./ports.js";
 
 export interface RollAllResult {
@@ -20,7 +20,7 @@ export interface RollAllResult {
 export function rollAllInitiativeUseCase(
 	store: EncounterStore,
 	rollDice: () => number,
-	getCreature: (id: CreatureId) => Creature | undefined,
+	getCreature: (id: CreatureId) => AnyCreature | undefined,
 	mode: RollMode = "normal",
 ): RollAllResult | DomainError {
 	let encounter = store.get();
@@ -37,11 +37,7 @@ export function rollAllInitiativeUseCase(
 			continue;
 		}
 
-		const { modifier } = calculateInitiative({
-			dexScore: creature.abilities.dex,
-			cr: creature.cr,
-			initiativeProficiency: creature.initiativeProficiency,
-		});
+		const modifier = creatureInitiativeModifier(creature);
 		const roll1 = rollDice();
 		const effectiveRoll =
 			mode === "normal" ? roll1 : selectRoll(roll1, rollDice(), mode);

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

@@ -1,8 +1,7 @@
 import {
+	type AnyCreature,
 	type CombatantId,
-	type Creature,
 	type CreatureId,
-	calculateInitiative,
 	type DomainError,
 	type DomainEvent,
 	isDomainError,
@@ -11,13 +10,14 @@ import {
 	selectRoll,
 	setInitiative,
 } from "@initiative/domain";
+import { creatureInitiativeModifier } from "./creature-initiative-modifier.js";
 import type { EncounterStore } from "./ports.js";
 
 export function rollInitiativeUseCase(
 	store: EncounterStore,
 	combatantId: CombatantId,
 	diceRolls: readonly [number, ...number[]],
-	getCreature: (id: CreatureId) => Creature | undefined,
+	getCreature: (id: CreatureId) => AnyCreature | undefined,
 	mode: RollMode = "normal",
 ): DomainEvent[] | DomainError {
 	const encounter = store.get();
@@ -48,11 +48,7 @@ export function rollInitiativeUseCase(
 		};
 	}
 
-	const { modifier } = calculateInitiative({
-		dexScore: creature.abilities.dex,
-		cr: creature.cr,
-		initiativeProficiency: creature.initiativeProficiency,
-	});
+	const modifier = creatureInitiativeModifier(creature);
 	const effectiveRoll =
 		mode === "normal"
 			? diceRolls[0]

packages/application/src/set-condition-value-use-case.ts

@@ -0,0 +1,20 @@
+import {
+	type CombatantId,
+	type ConditionId,
+	type DomainError,
+	type DomainEvent,
+	setConditionValue,
+} from "@initiative/domain";
+import type { EncounterStore } from "./ports.js";
+import { runEncounterAction } from "./run-encounter-action.js";
+
+export function setConditionValueUseCase(
+	store: EncounterStore,
+	combatantId: CombatantId,
+	conditionId: ConditionId,
+	value: number,
+): DomainEvent[] | DomainError {
+	return runEncounterAction(store, (encounter) =>
+		setConditionValue(encounter, combatantId, conditionId, value),
+	);
+}