feat(scene): shared zoom/pan for control and presentation

Keep effects pinned to map coordinates when the viewport changes; materials/NPC overlays stay screen-fixed.

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

app/renderer/shared/effects/PxiEffectsOverlay.pointer.test.ts

@@ -38,3 +38,11 @@ void test('PxiEffectsOverlay: lazy VFX packs + idle ticker stop', () => {
   );
   assert.ok(src.includes('Lazy VFX'));
 });
+
+void test('PxiEffectsOverlay: эффекты перекладываются при смене viewport (зум/пан)', () => {
+  const src = fs.readFileSync(path.join(here, 'PxiEffectsOverlay.tsx'), 'utf8');
+  assert.ok(src.includes('relayoutInstanceNode'));
+  assert.ok(src.includes('instanceContentSig'));
+  assert.ok(src.includes('viewportSig'));
+  assert.match(src, /\$\{contentSig\}@\$\{viewportSig\(viewport\)\}/);
+});