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/domain/src/__tests__/toggle-condition.test.ts

@@ -1,14 +1,18 @@
 import { describe, expect, it } from "vitest";
-import type { ConditionId } from "../conditions.js";
+import type { ConditionEntry, ConditionId } from "../conditions.js";
 import { CONDITION_DEFINITIONS } from "../conditions.js";
-import { toggleCondition } from "../toggle-condition.js";
+import {
+	decrementCondition,
+	setConditionValue,
+	toggleCondition,
+} from "../toggle-condition.js";
 import type { Combatant, Encounter } from "../types.js";
 import { combatantId, isDomainError } from "../types.js";
 import { expectDomainError } from "./test-helpers.js";
 
 function makeCombatant(
 	name: string,
-	conditions?: readonly ConditionId[],
+	conditions?: readonly ConditionEntry[],
 ): Combatant {
 	return conditions
 		? { id: combatantId(name), name, conditions }
@@ -32,7 +36,7 @@ describe("toggleCondition", () => {
 		const e = enc([makeCombatant("A")]);
 		const { encounter, events } = success(e, "A", "blinded");
 
-		expect(encounter.combatants[0].conditions).toEqual(["blinded"]);
+		expect(encounter.combatants[0].conditions).toEqual([{ id: "blinded" }]);
 		expect(events).toEqual([
 			{
 				type: "ConditionAdded",
@@ -43,7 +47,7 @@ describe("toggleCondition", () => {
 	});
 
 	it("removes a condition when already present", () => {
-		const e = enc([makeCombatant("A", ["blinded"])]);
+		const e = enc([makeCombatant("A", [{ id: "blinded" }])]);
 		const { encounter, events } = success(e, "A", "blinded");
 
 		expect(encounter.combatants[0].conditions).toBeUndefined();
@@ -57,14 +61,17 @@ describe("toggleCondition", () => {
 	});
 
 	it("maintains definition order when adding conditions", () => {
-		const e = enc([makeCombatant("A", ["poisoned"])]);
+		const e = enc([makeCombatant("A", [{ id: "poisoned" }])]);
 		const { encounter } = success(e, "A", "blinded");
 
-		expect(encounter.combatants[0].conditions).toEqual(["blinded", "poisoned"]);
+		expect(encounter.combatants[0].conditions).toEqual([
+			{ id: "blinded" },
+			{ id: "poisoned" },
+		]);
 	});
 
 	it("prevents duplicate conditions", () => {
-		const e = enc([makeCombatant("A", ["blinded"])]);
+		const e = enc([makeCombatant("A", [{ id: "blinded" }])]);
 		// Toggling blinded again removes it, not duplicates
 		const { encounter } = success(e, "A", "blinded");
 		expect(encounter.combatants[0].conditions).toBeUndefined();
@@ -96,7 +103,7 @@ describe("toggleCondition", () => {
 	});
 
 	it("normalizes empty array to undefined on removal", () => {
-		const e = enc([makeCombatant("A", ["charmed"])]);
+		const e = enc([makeCombatant("A", [{ id: "charmed" }])]);
 		const { encounter } = success(e, "A", "charmed");
 
 		expect(encounter.combatants[0].conditions).toBeUndefined();
@@ -110,6 +117,91 @@ describe("toggleCondition", () => {
 			const result = success(e, "A", cond);
 			e = result.encounter;
 		}
-		expect(e.combatants[0].conditions).toEqual(order);
+		expect(e.combatants[0].conditions).toEqual(order.map((id) => ({ id })));
+	});
+});
+
+describe("setConditionValue", () => {
+	it("adds a valued condition at the specified value", () => {
+		const e = enc([makeCombatant("A")]);
+		const result = setConditionValue(e, combatantId("A"), "frightened", 2);
+		if (isDomainError(result)) throw new Error(result.message);
+
+		expect(result.encounter.combatants[0].conditions).toEqual([
+			{ id: "frightened", value: 2 },
+		]);
+		expect(result.events).toEqual([
+			{
+				type: "ConditionAdded",
+				combatantId: combatantId("A"),
+				condition: "frightened",
+				value: 2,
+			},
+		]);
+	});
+
+	it("updates the value of an existing condition", () => {
+		const e = enc([makeCombatant("A", [{ id: "frightened", value: 1 }])]);
+		const result = setConditionValue(e, combatantId("A"), "frightened", 3);
+		if (isDomainError(result)) throw new Error(result.message);
+
+		expect(result.encounter.combatants[0].conditions).toEqual([
+			{ id: "frightened", value: 3 },
+		]);
+	});
+
+	it("removes condition when value is 0", () => {
+		const e = enc([makeCombatant("A", [{ id: "frightened", value: 2 }])]);
+		const result = setConditionValue(e, combatantId("A"), "frightened", 0);
+		if (isDomainError(result)) throw new Error(result.message);
+
+		expect(result.encounter.combatants[0].conditions).toBeUndefined();
+		expect(result.events[0].type).toBe("ConditionRemoved");
+	});
+
+	it("rejects unknown condition", () => {
+		const e = enc([makeCombatant("A")]);
+		const result = setConditionValue(
+			e,
+			combatantId("A"),
+			"flying" as ConditionId,
+			1,
+		);
+		expectDomainError(result, "unknown-condition");
+	});
+});
+
+describe("decrementCondition", () => {
+	it("decrements value by 1", () => {
+		const e = enc([makeCombatant("A", [{ id: "frightened", value: 3 }])]);
+		const result = decrementCondition(e, combatantId("A"), "frightened");
+		if (isDomainError(result)) throw new Error(result.message);
+
+		expect(result.encounter.combatants[0].conditions).toEqual([
+			{ id: "frightened", value: 2 },
+		]);
+	});
+
+	it("removes condition when value reaches 0", () => {
+		const e = enc([makeCombatant("A", [{ id: "frightened", value: 1 }])]);
+		const result = decrementCondition(e, combatantId("A"), "frightened");
+		if (isDomainError(result)) throw new Error(result.message);
+
+		expect(result.encounter.combatants[0].conditions).toBeUndefined();
+		expect(result.events[0].type).toBe("ConditionRemoved");
+	});
+
+	it("removes non-valued condition (value undefined treated as 1)", () => {
+		const e = enc([makeCombatant("A", [{ id: "blinded" }])]);
+		const result = decrementCondition(e, combatantId("A"), "blinded");
+		if (isDomainError(result)) throw new Error(result.message);
+
+		expect(result.encounter.combatants[0].conditions).toBeUndefined();
+	});
+
+	it("returns error for inactive condition", () => {
+		const e = enc([makeCombatant("A")]);
+		const result = decrementCondition(e, combatantId("A"), "frightened");
+		expectDomainError(result, "condition-not-active");
 	});
 });