feat: multi-material overlays, presentation guides, and release prebuilds

Align control/presentation with presentation screen rect and darkness z-order; sync window titles and session window cleanup. Pack Win/Mac/Linux with npmRebuild disabled and release-native-prep for classic-level and sharp.

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

scripts/release-mac-prep.test.mjs

@@ -3,15 +3,33 @@ import fs from 'node:fs';
 import os from 'node:os';
 import path from 'node:path';
 import test from 'node:test';
-import { fileURLToPath } from 'node:url';
 
 import { macSharpImgPackagesToInstall } from './release-mac-prep.mjs';
 
-const root = path.resolve(path.dirname(fileURLToPath(import.meta.url)), '..');
-
 void test('macSharpImgPackagesToInstall: empty when all four @img darwin packages exist', () => {
-  const missing = macSharpImgPackagesToInstall(root);
-  assert.deepEqual(missing, []);
+  const tmp = fs.mkdtempSync(path.join(os.tmpdir(), 'mac-sharp-all-'));
+  try {
+    const sharpOpt = {
+      '@img/sharp-darwin-arm64': '0.34.5',
+      '@img/sharp-libvips-darwin-arm64': '1.2.4',
+      '@img/sharp-darwin-x64': '0.34.5',
+      '@img/sharp-libvips-darwin-x64': '1.2.4',
+    };
+    fs.mkdirSync(path.join(tmp, 'node_modules', 'sharp'), { recursive: true });
+    fs.writeFileSync(
+      path.join(tmp, 'node_modules', 'sharp', 'package.json'),
+      JSON.stringify({ optionalDependencies: sharpOpt }),
+    );
+    for (const name of Object.keys(sharpOpt)) {
+      const dir = path.join(tmp, 'node_modules', name);
+      fs.mkdirSync(dir, { recursive: true });
+      fs.writeFileSync(path.join(dir, 'package.json'), '{}');
+    }
+    const missing = macSharpImgPackagesToInstall(tmp);
+    assert.deepEqual(missing, []);
+  } finally {
+    fs.rmSync(tmp, { recursive: true, force: true });
+  }
 });
 
 void test('macSharpImgPackagesToInstall: lists missing darwin-x64 on arm64-only tree', () => {