docs: lock scope to Telegram / 文件收斂為 Telegram 單平台並新增 V1 設計

README.md

@@ -28,11 +28,13 @@
 - 將使用者選擇映射到對話狀態
 - 保留使用者直接打字而不按按鈕的能力
 
-### Phase 1 目標
+### 專案目標平台
 
-Phase 1 先做 **Telegram**。
+這個專案目前 **固定只做 Telegram**。
 
-原因很簡單：Telegram 已經支援 inline keyboard 和 callback payload，是最適合先驗證這個互動模型的平台。
+不考慮 Discord、Slack 或其他 channel。
+
+所有設計、狀態結構、callback 流程、驗證方式，都以 Telegram 為唯一目標平台。
 
 ### 預期行為
 
@@ -158,11 +160,13 @@ This repository is only for the reply-end control feature, including:
 - mapping user choice into conversation state
 - preserving the ability to type freely instead of pressing a button
 
-### Phase 1 target
+### Target platform
 
-Phase 1 targets **Telegram** first.
+This project is **Telegram-only** for now.
 
-Telegram is the easiest first platform because it already supports inline keyboards and callback payloads, which makes it a good place to validate the interaction model.
+Discord, Slack, and other channels are explicitly out of scope.
+
+All design, state handling, callback flow, and testing will assume Telegram as the only target platform.
 
 ### Expected behavior
 
@@ -250,4 +254,5 @@ Phase 1 will likely need at least these layers:
 
 - repository created
 - README expanded into a formal bilingual project description
+- scope narrowed to Telegram-only
 - technical design and implementation have not started yet