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/components/source-manager.tsx

@@ -9,12 +9,15 @@ import {
 import type { CachedSourceInfo } from "../adapters/ports.js";
 import { useAdapters } from "../contexts/adapter-context.js";
 import { useBestiaryContext } from "../contexts/bestiary-context.js";
+import { useRulesEditionContext } from "../contexts/rules-edition-context.js";
 import { Button } from "./ui/button.js";
 import { Input } from "./ui/input.js";
 
 export function SourceManager() {
 	const { bestiaryCache } = useAdapters();
 	const { refreshCache } = useBestiaryContext();
+	const { edition } = useRulesEditionContext();
+	const system = edition === "pf2e" ? "pf2e" : "dnd";
 	const [sources, setSources] = useState<CachedSourceInfo[]>([]);
 	const [filter, setFilter] = useState("");
 	const [optimisticSources, applyOptimistic] = useOptimistic(
@@ -29,9 +32,9 @@ export function SourceManager() {
 	);
 
 	const loadSources = useCallback(async () => {
-		const cached = await bestiaryCache.getCachedSources();
+		const cached = await bestiaryCache.getCachedSources(system);
 		setSources(cached);
-	}, [bestiaryCache]);
+	}, [bestiaryCache, system]);
 
 	useEffect(() => {
 		void loadSources();
@@ -39,7 +42,7 @@ export function SourceManager() {
 
 	const handleClearSource = async (sourceCode: string) => {
 		applyOptimistic({ type: "remove", sourceCode });
-		await bestiaryCache.clearSource(sourceCode);
+		await bestiaryCache.clearSource(system, sourceCode);
 		await loadSources();
 		void refreshCache();
 	};