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/adapters/bestiary-cache.ts

@@ -1,23 +1,25 @@
-import type { Creature, CreatureId } from "@initiative/domain";
+import type { AnyCreature, CreatureId } from "@initiative/domain";
 import { type IDBPDatabase, openDB } from "idb";
 
 const DB_NAME = "initiative-bestiary";
 const STORE_NAME = "sources";
-const DB_VERSION = 3;
+const DB_VERSION = 4;
 
 interface CachedSourceInfo {
 	readonly sourceCode: string;
 	readonly displayName: string;
 	readonly creatureCount: number;
 	readonly cachedAt: number;
+	readonly system?: string;
 }
 
 interface CachedSourceRecord {
 	sourceCode: string;
 	displayName: string;
-	creatures: Creature[];
+	creatures: AnyCreature[];
 	cachedAt: number;
 	creatureCount: number;
+	system?: string;
 }
 
 let db: IDBPDatabase | null = null;
@@ -26,6 +28,10 @@ let dbFailed = false;
 // In-memory fallback when IndexedDB is unavailable
 const memoryStore = new Map<string, CachedSourceRecord>();
 
+function scopedKey(system: string, sourceCode: string): string {
+	return `${system}:${sourceCode}`;
+}
+
 async function getDb(): Promise<IDBPDatabase | null> {
 	if (db) return db;
 	if (dbFailed) return null;
@@ -58,60 +64,77 @@ async function getDb(): Promise<IDBPDatabase | null> {
 }
 
 export async function cacheSource(
+	system: string,
 	sourceCode: string,
 	displayName: string,
-	creatures: Creature[],
+	creatures: AnyCreature[],
 ): Promise<void> {
+	const key = scopedKey(system, sourceCode);
 	const record: CachedSourceRecord = {
-		sourceCode,
+		sourceCode: key,
 		displayName,
 		creatures,
 		cachedAt: Date.now(),
 		creatureCount: creatures.length,
+		system,
 	};
 
 	const database = await getDb();
 	if (database) {
 		await database.put(STORE_NAME, record);
 	} else {
-		memoryStore.set(sourceCode, record);
+		memoryStore.set(key, record);
 	}
 }
 
-export async function isSourceCached(sourceCode: string): Promise<boolean> {
+export async function isSourceCached(
+	system: string,
+	sourceCode: string,
+): Promise<boolean> {
+	const key = scopedKey(system, sourceCode);
 	const database = await getDb();
 	if (database) {
-		const record = await database.get(STORE_NAME, sourceCode);
+		const record = await database.get(STORE_NAME, key);
 		return record !== undefined;
 	}
-	return memoryStore.has(sourceCode);
+	return memoryStore.has(key);
 }
 
-export async function getCachedSources(): Promise<CachedSourceInfo[]> {
+export async function getCachedSources(
+	system?: string,
+): Promise<CachedSourceInfo[]> {
 	const database = await getDb();
+	let records: CachedSourceRecord[];
 	if (database) {
-		const all: CachedSourceRecord[] = await database.getAll(STORE_NAME);
-		return all.map((r) => ({
-			sourceCode: r.sourceCode,
-			displayName: r.displayName,
-			creatureCount: r.creatureCount,
-			cachedAt: r.cachedAt,
-		}));
+		records = await database.getAll(STORE_NAME);
+	} else {
+		records = [...memoryStore.values()];
 	}
-	return [...memoryStore.values()].map((r) => ({
-		sourceCode: r.sourceCode,
+
+	const filtered = system
+		? records.filter((r) => r.system === system)
+		: records;
+	return filtered.map((r) => ({
+		sourceCode: r.system
+			? r.sourceCode.slice(r.system.length + 1)
+			: r.sourceCode,
 		displayName: r.displayName,
 		creatureCount: r.creatureCount,
 		cachedAt: r.cachedAt,
+		system: r.system,
 	}));
 }
 
-export async function clearSource(sourceCode: string): Promise<void> {
+export async function clearSource(
+	system: string,
+	sourceCode: string,
+): Promise<void> {
+	const key = scopedKey(system, sourceCode);
 	const database = await getDb();
 	if (database) {
-		await database.delete(STORE_NAME, sourceCode);
+		await database.delete(STORE_NAME, key);
 	} else {
-		memoryStore.delete(sourceCode);
+		memoryStore.delete(key);
 	}
 }
 
@@ -125,9 +148,9 @@ export async function clearAll(): Promise<void> {
 }
 
 export async function loadAllCachedCreatures(): Promise<
-	Map<CreatureId, Creature>
+	Map<CreatureId, AnyCreature>
 > {
-	const map = new Map<CreatureId, Creature>();
+	const map = new Map<CreatureId, AnyCreature>();
 	const database = await getDb();
 
 	let records: CachedSourceRecord[];