refactor(frontend): 拆 types.ts(871) / ws.ts::dispatchFrame(266)（纯搬移 + barrel）

执行方案 DevDocs/audit/_plan.md 阶段 0 · G0-D：
- lib/types.ts(871) → lib/types/ 11 个域文件 + 14 行 `export *` barrel（仿 lib/api.ts 先例）
  chat / ws / session / agent / flow / persona / api / admin(269) / adminWrite(176) / kook /
  notification
- lib/ws.ts(494) → 203 行入口 + lib/ws/handlers/ 8 文件；dispatchFrame(266 行) 改为按组
  分发链（7 个 handler 各持一组 case，命中 return true，未命中走原 default 兜底），
  33 个 case 标签一一守恒

机械证明：type 导出集 86 个守恒（拆后并集 diff 为空）；去掉空行与 import/export 语句后
**784=784 行、排序 diff 为空**；dispatchFrame 的 case 标签集 33=33 守恒；ws.ts 的
scheduleReconnect 至文件尾与 HEAD 字节级一致。
65 个 lib/types 消费方 + 3 个 lib/ws 消费方**零改动**通过 —— tsc 0 错误正是这一点的强判据。

验证：npx tsc --noEmit 0 错误；npm run build 成功；9 个前端逻辑测试全绿（含真实驱动
拆后 dispatchFrame 的 messageSync 54 checks 与 personaSession 23 checks）；
最大文件 admin.ts 269 行、最大函数 openSocket 72 行（均达标）。

frontend/web/src/lib/ws/handlers/message.ts

@@ -0,0 +1,92 @@
+import { messageEventApplies } from "../../../store/useAppStore";
+import { MODES, type ChatMessage, type Mode } from "../../types";
+import { parseAdminChannelMessage, parsePersistedMessage, toRecord } from "../../wsParse";
+import type { FrameEvent, FramePayload, StoreState } from "./shared";
+
+/** The fields of a `message_edited` payload the chat needs: the edited message's
+ *  id and its new content. `sessionId` is carried inside the broadcast DTO (and on
+ *  the frame envelope) so the frame can be filtered; `mode`/`mood` are optional —
+ *  an edit never changes them, but the DTO carries them for completeness. */
+interface MessageEdited {
+  id: string;
+  content: string;
+  sessionId?: string;
+  mode?: Mode;
+  mood?: string;
+}
+
+/** Narrow a `message_edited` payload (the updated message DTO), or null when it is
+ *  unusable. `content` is required: an edit always carries the new text, and a
+ *  frame without it must not blank out a rendered bubble. */
+function parseMessageEdited(data: unknown): MessageEdited | null {
+  const r = toRecord(data);
+  if (!r || typeof r.id !== "string" || r.id === "" || typeof r.content !== "string") {
+    return null;
+  }
+  return {
+    id: r.id,
+    content: r.content,
+    sessionId: typeof r.sessionId === "string" ? r.sessionId : undefined,
+    mode:
+      typeof r.mode === "string" && MODES.includes(r.mode as Mode)
+        ? (r.mode as Mode)
+        : undefined,
+    mood: typeof r.mood === "string" ? r.mood : undefined,
+  };
+}
+
+/** 消息落库/编辑/删除帧处理组：message_persisted / message_edited /
+ *  message_deleted / channel_persisted。命中（含组内主动丢弃）返回 true，
+ *  未命中返回 false 交给下一组。 */
+export function handleMessageEvent(ev: FrameEvent, r: FramePayload, s: StoreState): boolean {
+  switch (ev.type) {
+    case "message_persisted": {
+      // design/16 §4.2 — a user or assistant message was persisted and broadcast
+      // with its backend id. Only surface messages for the active session; the
+      // store dedups by id and adopts the local optimistic bubble (uid → backend
+      // id), so both the originating and remote browsers converge on one message.
+      const msg = parsePersistedMessage(r?.message);
+      if (msg && msg.sessionId === s.activeSessionId) {
+        s.appendOrUpdateMessage(msg);
+      }
+      return true;
+    }
+    case "message_edited": {
+      // design/16 §4.2 (D3 edit path) — the stored message's content was changed
+      // and broadcast with the updated DTO. The backend row stays the single source
+      // of truth; this only re-renders the bubble, and only in the session it
+      // belongs to (same filter as message_persisted). Patch by id — an id we do not
+      // hold is another session's (or an already-gone) message, never a new row.
+      const edit = parseMessageEdited(ev.data);
+      if (!edit) return true;
+      if (messageEventApplies(edit.sessionId ?? ev.sessionId, s.activeSessionId)) {
+        const patch: Partial<ChatMessage> = { content: edit.content };
+        if (edit.mode) patch.mode = edit.mode;
+        if (edit.mood) patch.mood = edit.mood;
+        s.updateMessageById(edit.id, patch);
+      }
+      return true;
+    }
+    case "message_deleted": {
+      // design/16 §4.2 (D3 delete path) — the message was removed server-side, so
+      // drop it by id instead of waiting for a manual re-read. The id is globally
+      // unique; sessionId is advisory and, when present, must be the active one.
+      const id = r && typeof r.id === "string" ? r.id : "";
+      if (id && messageEventApplies(ev.sessionId, s.activeSessionId)) {
+        s.removeMessageById(id);
+      }
+      return true;
+    }
+    case "channel_persisted": {
+      // design/16 §4.6 §4 — an isolated (group/stranger) channel message was
+      // persisted and broadcast for the IM adapter log page. The web chat has no
+      // handler for this type, so it never reaches the active conversation; the
+      // admin adapter log consumes it via `channelEvents` to append in realtime.
+      const msg = parseAdminChannelMessage(r?.message);
+      if (msg) s.pushChannelEvent(msg);
+      return true;
+    }
+    default:
+      return false;
+  }
+}