docs: archived README banner + content; replace lost domains where present

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: claude

README.md

@@ -1,2 +1,20 @@
-# TegroBusiness-WebViewApp
- TegroBusiness-WebViewApp
+# Tegro Business — Android WebView App (Sample)
+
+> ⚠️ **Archived — early prototype / reference, no longer maintained.**
+> Kept public for transparency and research. See our actively maintained projects in the **[Tegro open-source org](https://github.com/TegroTON)** — DEX [tegro.finance](https://tegro.finance) · Payments [tegro.money](https://tegro.money) · [all repositories »](https://github.com/orgs/TegroTON/repositories)
+
+A **sample Android application** that wraps the Tegro payment/business web interface in a native WebView — a reference for shipping the web app as an Android APK/AAB.
+
+## Overview
+Demonstrates packaging a Tegro web experience into a native Android shell using WebView. Prebuilt `app-release.apk` / `app-release.aab` are included as samples.
+
+## Tech Stack
+- **Language:** Kotlin (Android)
+- **UI:** Native WebView wrapper
+
+## Status
+🚧 Sample / reference only.
+
+## Related
+- 💳 Payments — [tegro.money](https://tegro.money)
+- 🏠 Open-source org — [github.com/TegroTON](https://github.com/TegroTON)