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>

apps/web/src/hooks/__tests__/encounter-reducer.test.ts

@@ -1,8 +1,4 @@
-import type {
-	BestiaryIndexEntry,
-	ConditionId,
-	PlayerCharacter,
-} from "@initiative/domain";
+import type { ConditionId, PlayerCharacter } from "@initiative/domain";
 import {
 	combatantId,
 	createEncounter,
@@ -11,6 +7,7 @@ import {
 	playerCharacterId,
 } from "@initiative/domain";
 import { describe, expect, it } from "vitest";
+import type { SearchResult } from "../use-bestiary.js";
 import { type EncounterState, encounterReducer } from "../use-encounter.js";
 
 function emptyState(): EncounterState {
@@ -45,9 +42,11 @@ function stateWithHp(name: string, maxHp: number): EncounterState {
 	});
 }
 
-const BESTIARY_ENTRY: BestiaryIndexEntry = {
+const BESTIARY_ENTRY: SearchResult = {
+	system: "dnd",
 	name: "Goblin",
 	source: "MM",
+	sourceDisplayName: "Monster Manual",
 	ac: 15,
 	hp: 7,
 	dex: 14,
@@ -57,6 +56,19 @@ const BESTIARY_ENTRY: BestiaryIndexEntry = {
 	type: "humanoid",
 };
 
+const PF2E_BESTIARY_ENTRY: SearchResult = {
+	system: "pf2e",
+	name: "Goblin Warrior",
+	source: "B1",
+	sourceDisplayName: "Bestiary",
+	level: -1,
+	ac: 16,
+	hp: 6,
+	perception: 5,
+	size: "small",
+	type: "humanoid",
+};
+
 describe("encounterReducer", () => {
 	describe("add-combatant", () => {
 		it("adds a combatant and pushes undo", () => {
@@ -236,7 +248,9 @@ describe("encounterReducer", () => {
 				conditionId: "blinded" as ConditionId,
 			});
 
-			expect(next.encounter.combatants[0].conditions).toContain("blinded");
+			expect(next.encounter.combatants[0].conditions).toContainEqual({
+				id: "blinded",
+			});
 		});
 
 		it("toggles concentration", () => {
@@ -327,6 +341,19 @@ describe("encounterReducer", () => {
 			expect(names).toContain("Goblin 1");
 			expect(names).toContain("Goblin 2");
 		});
+
+		it("adds PF2e creature with HP, AC, and creatureId", () => {
+			const next = encounterReducer(emptyState(), {
+				type: "add-from-bestiary",
+				entry: PF2E_BESTIARY_ENTRY,
+			});
+
+			const c = next.encounter.combatants[0];
+			expect(c.name).toBe("Goblin Warrior");
+			expect(c.maxHp).toBe(6);
+			expect(c.ac).toBe(16);
+			expect(c.creatureId).toBe("b1:goblin-warrior");
+		});
 	});
 
 	describe("add-multiple-from-bestiary", () => {