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/playerToken/usePlayerImageUrl.ts

@@ -0,0 +1,26 @@
+import { useEffect, useState } from 'react';
+
+import { ipcChannels } from '../../../shared/ipc/contracts';
+import type { PlayerId } from '../../../shared/types';
+import { getDndApi } from '../dndApi';
+
+export function usePlayerImageUrl(playerId: PlayerId | null | undefined): string | null {
+  const api = getDndApi();
+  const [url, setUrl] = useState<string | null>(null);
+
+  useEffect(() => {
+    if (!playerId) {
+      setUrl(null);
+      return;
+    }
+    let cancelled = false;
+    void api.invoke(ipcChannels.players.imageUrl, { id: playerId }).then((res) => {
+      if (!cancelled) setUrl(res.url);
+    });
+    return () => {
+      cancelled = true;
+    };
+  }, [api, playerId]);
+
+  return url;
+}