refactor(stores): split state and event unions into separate files

Extract `<Name>Context` interface + `initialContext` const into
`<name>-context.ts` and the event union into `<name>-events.ts` for
all four state machines (auth, chat, sidebar, user) under src/stores/.

- `*-machine.ts` keeps helpers, actors, actions, and the
  `setup().createMachine()` body; re-exports the types/initial value
  to preserve its public API.
- `*-types.ts` re-exports from the new files for backward compatibility
  (sidebar keeps enum re-exports, chat keeps GuestChatQuota).
- `index.ts` barrels updated to re-export the new files.
- Removed unused model imports (AuthMode, AuthPanelMode) from
  auth-machine.ts; kept LoginType, UiMessage, UserView where still
  used by actors/helpers.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/stores/chat/chat-context.ts

@@ -0,0 +1,30 @@
+/**
+ * Chat 状态机：Context 形状 + 初始值
+ *
+ * 注：GuestChatQuota 仍位于 chat-machine.ts（属于业务常量，与上下文配对紧密）。
+ */
+import type { UiMessage } from "@/models/chat/ui-message";
+
+export interface ChatContext {
+  messages: UiMessage[];
+  isReplyingAI: boolean;
+  isGuest: boolean;
+  guestRemainingQuota: number;
+  guestTotalQuota: number;
+  quotaExceededTrigger: number;
+  isLoadingMore: boolean;
+  hasMore: boolean;
+  historyOffset: number;
+}
+
+export const initialContext: ChatContext = {
+  messages: [],
+  isReplyingAI: false,
+  isGuest: true,
+  guestRemainingQuota: 40,
+  guestTotalQuota: 50,
+  quotaExceededTrigger: 0,
+  isLoadingMore: false,
+  hasMore: true,
+  historyOffset: 0,
+};

src/stores/chat/chat-events.ts

@@ -0,0 +1,23 @@
+/**
+ * Chat 状态机：事件联合
+ *
+ * 事件名与原 Dart ChatEvent 对齐。
+ */
+export type ChatEvent =
+  | { type: "ChatInit" }
+  | { type: "ChatScreenVisible" }
+  | { type: "ChatScreenInvisible" }
+  | { type: "ChatSendMessage"; content: string }
+  | { type: "ChatSendImage"; imageBase64: string }
+  | { type: "ChatLoadMoreHistory" }
+  | {
+      type: "ChatAISentenceReceived";
+      index: number;
+      text: string;
+      total: number;
+      done: boolean;
+    }
+  | { type: "ChatWebSocketError"; errorMessage: string }
+  | { type: "ChatWebSocketConnected"; userId: string }
+  | { type: "ChatQuotaExceeded" }
+  | { type: "ChatAuthStatusChanged" };

src/stores/chat/chat-machine.ts

@@ -23,32 +23,8 @@ import { AuthStorage } from "@/data/storage/auth/auth_storage";
 import { formatDate } from "@/utils/date";
 import { Result } from "@/utils/result";
 
-// ============================================================
-// Context
-// ============================================================
-export interface ChatContext {
-  messages: UiMessage[];
-  isReplyingAI: boolean;
-  isGuest: boolean;
-  guestRemainingQuota: number;
-  guestTotalQuota: number;
-  quotaExceededTrigger: number;
-  isLoadingMore: boolean;
-  hasMore: boolean;
-  historyOffset: number;
-}
-
-const initialContext: ChatContext = {
-  messages: [],
-  isReplyingAI: false,
-  isGuest: true,
-  guestRemainingQuota: 40,
-  guestTotalQuota: 50,
-  quotaExceededTrigger: 0,
-  isLoadingMore: false,
-  hasMore: true,
-  historyOffset: 0,
-};
+import { ChatContext, initialContext } from "./chat-context";
+import type { ChatEvent } from "./chat-events";
 
 /** 游客配额阈值（与 Dart `GuestChatQuota` 保持一致） */
 export const GuestChatQuota = {
@@ -56,27 +32,10 @@ export const GuestChatQuota = {
   quotaExhausted: 0,
 } as const;
 
-// ============================================================
-// Events
-// ============================================================
-export type ChatEvent =
-  | { type: "ChatInit" }
-  | { type: "ChatScreenVisible" }
-  | { type: "ChatScreenInvisible" }
-  | { type: "ChatSendMessage"; content: string }
-  | { type: "ChatSendImage"; imageBase64: string }
-  | { type: "ChatLoadMoreHistory" }
-  | {
-      type: "ChatAISentenceReceived";
-      index: number;
-      text: string;
-      total: number;
-      done: boolean;
-    }
-  | { type: "ChatWebSocketError"; errorMessage: string }
-  | { type: "ChatWebSocketConnected"; userId: string }
-  | { type: "ChatQuotaExceeded" }
-  | { type: "ChatAuthStatusChanged" };
+// 重新导出 Context / Event 类型，保持 machine 文件的公共 API 不变
+export type { ChatContext } from "./chat-context";
+export { initialContext } from "./chat-context";
+export type { ChatEvent } from "./chat-events";
 
 // ============================================================
 // Helpers

src/stores/chat/chat-types.ts

@@ -3,9 +3,10 @@
  *
  * 原始文件定义了 ChatState 接口、ChatEvent 联合、initialChatState、GuestChatQuota。
  * 状态机重构后：
- *   - `ChatEvent` 联合由 `chat-machine.ts` 重新导出（保留类型）
+ *   - `ChatEvent` 联合由 `chat-events.ts` 导出
+ *   - Context 形状与初始值由 `chat-context.ts` 导出
  *   - `ChatState` 由 `chat-context.tsx` 导出（保持原 API 兼容）
- *   - `GuestChatQuota` 重新导出
+ *   - `GuestChatQuota` 仍由 `chat-machine.ts` 导出（业务常量，与上下文配对紧密）
  */
-export type { ChatEvent } from "./chat-machine";
+export type { ChatEvent } from "./chat-events";
 export { GuestChatQuota } from "./chat-machine";

src/stores/chat/index.ts

@@ -5,10 +5,13 @@
  *   - 业务类（Dart 风格 context/reducer/side-effects）已合并到 chat-machine.ts
  *   - 类型由 chat-types.ts 重新导出
  *   - React 入口为 chat-context.tsx（useMachine 包装）
+ *   - Context 形状与初始值位于 chat-context.ts
+ *   - 事件联合位于 chat-events.ts
  *
  * 注：chat-side-effects.ts 暂未删除（其中 WebSocket 长生命周期逻辑
  * 待下一轮迁移到 fromCallback actor）。
  */
 export * from "./chat-context";
+export * from "./chat-events";
 export * from "./chat-types";
 export { chatMachine } from "./chat-machine";