feat(players): app Players library and circular NPC tokens on scenes

Add userData players/teams, scene npcTokens with hex-inscribed sizing, session scale synced to presentation, and Playwright e2e coverage.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/renderer/shared/PresentationView.tsx

@@ -15,6 +15,8 @@ import { MaterialOverlay } from './materials/MaterialOverlay';
 import { useMaterialsOverlayState } from './materials/useMaterialsOverlayState';
 import { NpcsSceneOverlay } from './npcs/NpcsSceneOverlay';
 import { useNpcsOverlayState } from './npcs/useNpcsOverlayState';
+import { SceneNpcTokensOverlay } from './playerToken/SceneNpcTokensOverlay';
+import { useSceneNpcTokensSession } from './playerToken/useSceneNpcTokensSession';
 import { SceneOverlayHost } from './sceneOverlay/SceneOverlayHost';
 import { useSceneViewState } from './sceneView/useSceneViewState';
 import { SceneTokensOverlay } from './tokens/SceneTokensOverlay';
@@ -49,6 +51,7 @@ export function PresentationView({
   const [npcsOverlay] = useNpcsOverlayState();
   const appTokens = useAppTokens();
   const [sceneTokensSession] = useSceneTokensSession();
+  const [sceneNpcTokensSession] = useSceneNpcTokensSession();
   const [vp] = useVideoPlaybackState();
   const videoElRef = useRef<HTMLVideoElement | null>(null);
   const [contentRect, setContentRect] = React.useState<{ x: number; y: number; w: number; h: number } | null>(
@@ -177,6 +180,15 @@ export function PresentationView({
           viewport={contentRect}
         />
       ) : null}
+      {scene?.previewAssetType === 'image' && contentRect ? (
+        <SceneNpcTokensOverlay
+          placements={scene.npcTokens ?? []}
+          library={project?.npcs ?? []}
+          session={sceneNpcTokensSession}
+          viewport={contentRect}
+          grid={scene.grid}
+        />
+      ) : null}
       {scene?.previewAssetType === 'image' && contentRect ? (
         <SceneTrapsOverlay
           traps={scene.traps ?? []}