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/stat-block-panel.tsx

@@ -1,4 +1,4 @@
-import type { CreatureId } from "@initiative/domain";
+import type { Creature, CreatureId } from "@initiative/domain";
 import { PanelRightClose, Pin, PinOff } from "lucide-react";
 import type { ReactNode } from "react";
 import { useEffect, useState } from "react";
@@ -7,9 +7,10 @@ import { useSidePanelContext } from "../contexts/side-panel-context.js";
 import { useSwipeToDismiss } from "../hooks/use-swipe-to-dismiss.js";
 import { cn } from "../lib/utils.js";
 import { BulkImportPrompt } from "./bulk-import-prompt.js";
+import { DndStatBlock } from "./dnd-stat-block.js";
+import { Pf2eStatBlock } from "./pf2e-stat-block.js";
 import { SourceFetchPrompt } from "./source-fetch-prompt.js";
 import { SourceManager } from "./source-manager.js";
-import { StatBlock } from "./stat-block.js";
 import { Button } from "./ui/button.js";
 
 interface StatBlockPanelProps {
@@ -307,7 +308,10 @@ export function StatBlockPanel({
 		}
 
 		if (creature) {
-			return <StatBlock creature={creature} />;
+			if ("system" in creature && creature.system === "pf2e") {
+				return <Pf2eStatBlock creature={creature} />;
+			}
+			return <DndStatBlock creature={creature as Creature} />;
 		}
 
 		if (needsFetch && sourceCode) {