fix: stabilize public demo and align sorter twins

Document arhipovdan.ru DNS/TLS blocker, add production smoke and GPU
perf tooling, unify twin layout, and expand visual regression coverage.

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

src/vite-env.d.ts

@@ -1 +1,14 @@
 /// <reference types="vite/client" />
+
+import type { PerfSnapshot } from './domain/perfMetrics';
+
+declare global {
+  interface Window {
+    /** Live Three.js perf snapshot (getter) — only when ?perf=1 / PerfCollector mounted */
+    __PERF_SNAPSHOT__?: PerfSnapshot;
+    /** Clear frame-time samples and gl.info counters */
+    __PERF_RESET__?: () => void;
+  }
+}
+
+export {};