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/main/players/playersStore.test.ts

@@ -0,0 +1,70 @@
+import assert from 'node:assert/strict';
+import fs from 'node:fs/promises';
+import os from 'node:os';
+import path from 'node:path';
+import test from 'node:test';
+
+import { PlayersStore } from './playersStore';
+import { asPlayerId } from '../../shared/types/ids';
+
+async function withTempStore(run: (store: PlayersStore, root: string) => Promise<void>) {
+  const root = await fs.mkdtemp(path.join(os.tmpdir(), 'dnd-players-'));
+  const store = new PlayersStore(root);
+  try {
+    await run(store, root);
+  } finally {
+    await fs.rm(root, { recursive: true, force: true });
+  }
+}
+
+void test('PlayersStore upsert list delete and teams', async () => {
+  await withTempStore(async (store, root) => {
+    const png = path.join(root, 'sample.png');
+    // minimal 1x1 png
+    const buf = Buffer.from(
+      'iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mP8z8BQDwAEhQGAhKmMIQAAAABJRU5ErkJggg==',
+      'base64',
+    );
+    await fs.writeFile(png, buf);
+
+    const progress: number[] = [];
+    const player = await store.upsert(
+      { name: 'Ada', filePath: png, ringColor: '#112233', imageOffset: { x: 0.1, y: -0.1 } },
+      (p) => progress.push(p.percent),
+    );
+    assert.equal(player.name, 'Ada');
+    assert.equal(player.ringColor, '#112233');
+    assert.ok(progress.length > 0);
+    assert.equal(store.listPlayers().length, 1);
+
+    const team = await store.upsertTeam({ name: 'Party', color: '#abcdef' });
+    assert.equal(team.name, 'Party');
+    const assigned = await store.assignPlayerTeam(player.id, team.id);
+    assert.equal(assigned?.teamId, team.id);
+
+    await store.deleteTeam(team.id);
+    assert.equal(store.listTeams().length, 0);
+    assert.equal(store.getById(player.id)?.teamId, null);
+
+    await store.delete(player.id);
+    assert.equal(store.listPlayers().length, 0);
+  });
+});
+
+void test('PlayersStore persists across reload', async () => {
+  await withTempStore(async (store, root) => {
+    const png = path.join(root, 'sample.png');
+    await fs.writeFile(
+      png,
+      Buffer.from(
+        'iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mP8z8BQDwAEhQGAhKmMIQAAAABJRU5ErkJggg==',
+        'base64',
+      ),
+    );
+    const created = await store.upsert({ name: 'Bob', filePath: png });
+    const store2 = new PlayersStore(root);
+    await store2.ensureLoaded();
+    assert.equal(store2.listPlayers().length, 1);
+    assert.equal(store2.getById(asPlayerId(created.id))?.name, 'Bob');
+  });
+});