refactor(chat): remove legacy screen visibility events and use absolute state refs

- Remove ChatScreenVisible and ChatScreenInvisible events from chat state machine
- Remove legacy ChatInit event handler
- Migrate state transitions to use absolute references (#chat.guestSession, #chat.userSession, #chat.idle)
- Adjust legal text wording for Cozsweet privacy agreement

src/stores/chat/chat-events.ts

@@ -18,8 +18,6 @@
 export type ChatEvent =
   // 内部 UI 事件
   | { type: "ChatInit" }
-  | { type: "ChatScreenVisible" }
-  | { type: "ChatScreenInvisible" }
   // 鉴权生命周期（**用户**显式触发登录后由 chat-screen 派）
   | { type: "ChatGuestLogin" }
   | { type: "ChatNonGuestLogin"; token: string }

src/stores/chat/chat-machine.ts

@@ -297,10 +297,8 @@ export const chatMachine = setup({
     // ─────────────────────────────────────────────────────────────
     idle: {
       on: {
-        ChatGuestLogin: "guestSession",
-        ChatNonGuestLogin: "userSession",
-        // 兼容旧事件（**无**资源 —— 旧 chat-screen 还在派 ChatInit）
-        ChatInit: "guestSession",
+        ChatGuestLogin: "#chat.guestSession",
+        ChatNonGuestLogin: "#chat.userSession",
         ChatLoadMoreHistory: "loadingMoreHistory", // 旧逻辑保留（翻历史用）
       },
     },
@@ -345,10 +343,9 @@ export const chatMachine = setup({
               actions: "appendUserImage",
             },
             ChatLoadMoreHistory: "loadingMore",
-            ChatScreenInvisible: "idle", // 屏不可见 → idle
-            ChatLogout: "idle", // 登出 → idle
+            ChatLogout: "#chat.idle", // 登出 → idle
             // 跨态（游客 → email）
-            ChatNonGuestLogin: "userSession",
+            ChatNonGuestLogin: "#chat.userSession",
             ChatAISentenceReceived: {
               actions: "appendOrUpdateAISentence",
             },
@@ -426,10 +423,9 @@ export const chatMachine = setup({
               actions: "appendUserImage",
             },
             ChatLoadMoreHistory: "loadingMore",
-            ChatScreenInvisible: "idle", // 屏不可见 → idle（cleanup WS via parent state exit）
-            ChatLogout: "idle", // 登出 → idle（cleanup WS）
+            ChatLogout: "#chat.idle", // 登出 → idle（cleanup WS）
             // 跨态（email → 游客）
-            ChatGuestLogin: "guestSession",
+            ChatGuestLogin: "#chat.guestSession",
             ChatAISentenceReceived: {
               actions: "appendOrUpdateAISentence",
             },
@@ -501,10 +497,9 @@ export const chatMachine = setup({
           actions: "appendUserImage",
         },
         ChatLoadMoreHistory: "loadingMoreHistory",
-        ChatScreenInvisible: "idle",
-        ChatLogout: "idle",
-        ChatGuestLogin: "guestSession",
-        ChatNonGuestLogin: "userSession",
+        ChatLogout: "#chat.idle",
+        ChatGuestLogin: "#chat.guestSession",
+        ChatNonGuestLogin: "#chat.userSession",
         ChatAISentenceReceived: {
           actions: "appendOrUpdateAISentence",
         },