diff --git a/src/core/op.ts b/src/core/op.ts
new file mode 100644
index 0000000..5574e6a
--- /dev/null
+++ b/src/core/op.ts
@@ -0,0 +1,274 @@
+/* =====================================================================
+ * op.ts — 操作日志（Op Log）数据模型
+ *
+ * 所有对 deck 的变更都表达为 Op，通过纯函数 reducer 应用。
+ * Op 是可序列化、可回放、可逆的——为未来协同预留基础。
+ *
+ * 设计：
+ *   - 元素级粒度：update_element 带字段级 patch
+ *   - replace_deck 作为特殊 Op，进 undo 历史
+ *   - 每个 Op 可计算逆 Op（用于 undo）
+ *   - reducer 是纯函数：(deck, op) → newDeck
+ * ===================================================================== */
+import type { Deck, Slide, SlideElement, ElementStyle, BgKey } from './types'
+
+/* ---------- Op 类型定义 ---------- */
+
+export type OpType =
+  | 'add_slide'
+  | 'del_slide'
+  | 'move_slide'
+  | 'replace_slide'
+  | 'set_slide_bg'
+  | 'add_element'
+  | 'update_element'
+  | 'del_element'
+  | 'move_element_z'
+  | 'set_theme'
+  | 'replace_deck'
+
+export interface Op {
+  type: OpType
+  // 通用元数据（为协同预留）
+  clientId?: string
+  timestamp?: number
+  // 各类型的 payload（按 type 不同，只填对应字段）
+  [key: string]: unknown
+}
+
+/** 带逆操作的历史条目 */
+export interface HistoryEntry {
+  forward: Op
+  backward: Op
+}
+
+/* ---------- 工具 ---------- */
+
+function clone<T>(o: T): T { return JSON.parse(JSON.stringify(o)) }
+
+/** 在 deck 的某页里找元素 */
+function findEl(deck: Deck, slideIdx: number, elId: string): SlideElement | null {
+  const s = deck.slides[slideIdx]
+  if (!s) return null
+  return s.elements.find(e => e.id === elId) || null
+}
+
+/* ============================================================
+ * 纯函数 reducer：applyOp(deck, op) → newDeck
+ * 不 mutate 输入，返回新 deck
+ * ============================================================ */
+export function applyOp(inputDeck: Deck, op: Op): Deck {
+  const deck = clone(inputDeck)   // 深拷贝，不 mutate 原数据
+
+  switch (op.type) {
+    case 'add_slide': {
+      const atIndex = op.atIndex as number | undefined
+      const slide = op.slide as Slide
+      const idx = atIndex != null ? atIndex : deck.slides.length
+      deck.slides.splice(idx, 0, slide)
+      break
+    }
+
+    case 'del_slide': {
+      const index = op.index as number
+      if (deck.slides.length <= 1) break
+      deck.slides.splice(index, 1)
+      break
+    }
+
+    case 'move_slide': {
+      const from = op.from as number
+      const to = op.to as number
+      if (from === to || from < 0 || to < 0 || to >= deck.slides.length) break
+      const item = deck.slides.splice(from, 1)[0]
+      deck.slides.splice(to, 0, item)
+      break
+    }
+
+    case 'replace_slide': {
+      const index = op.index as number
+      const slide = op.slide as Slide
+      if (deck.slides[index]) {
+        slide.id = deck.slides[index].id   // 保持 id 不变
+      }
+      deck.slides[index] = slide
+      break
+    }
+
+    case 'set_slide_bg': {
+      const index = op.index as number
+      const bg = op.bg as BgKey
+      if (deck.slides[index]) {
+        deck.slides[index].background = bg
+      }
+      break
+    }
+
+    case 'add_element': {
+      const slideIdx = op.slideIdx as number
+      const element = op.element as SlideElement
+      const s = deck.slides[slideIdx]
+      if (s) s.elements.push(element)
+      break
+    }
+
+    case 'update_element': {
+      const slideIdx = op.slideIdx as number
+      const elementId = op.elementId as string
+      const patch = op.patch as Partial<SlideElement> & { style?: Record<string, unknown> }
+      const el = findEl(deck, slideIdx, elementId)
+      if (!el) break
+      if (patch.style) { Object.assign(el.style, patch.style) }
+      const rest = { ...patch }; delete (rest as Record<string, unknown>).style
+      Object.assign(el, rest)
+      break
+    }
+
+    case 'del_element': {
+      const slideIdx = op.slideIdx as number
+      const elementId = op.elementId as string
+      const s = deck.slides[slideIdx]
+      if (s) s.elements = s.elements.filter(e => e.id !== elementId)
+      break
+    }
+
+    case 'move_element_z': {
+      const slideIdx = op.slideIdx as number
+      const elementId = op.elementId as string
+      const dir = op.dir as number
+      const s = deck.slides[slideIdx]
+      if (!s) break
+      const i = s.elements.findIndex(e => e.id === elementId)
+      if (i < 0) break
+      const j = dir > 0 ? i + 1 : i - 1
+      if (j < 0 || j >= s.elements.length) break
+      const tmp = s.elements[i]; s.elements[i] = s.elements[j]; s.elements[j] = tmp
+      break
+    }
+
+    case 'set_theme': {
+      const theme = op.theme as string
+      deck.theme = theme
+      break
+    }
+
+    case 'replace_deck': {
+      const newDeck = op.deck as Deck
+      // 全量替换，但保留版本号
+      newDeck.v = deck.v
+      return newDeck
+    }
+
+    default:
+      // 未知 Op 类型，不修改
+      break
+  }
+
+  return deck
+}
+
+/* ============================================================
+ * 逆操作计算：invertOp(deck, op) → Op
+ * 根据当前 deck 状态，计算能撤销 op 的逆 Op
+ * ============================================================ */
+export function invertOp(inputDeck: Deck, op: Op): Op {
+  const deck = inputDeck   // 只读，不 clone
+
+  switch (op.type) {
+    case 'add_slide': {
+      // 逆：删除加的那页
+      const slide = op.slide as Slide
+      const idx = deck.slides.findIndex(s => s.id === slide.id)
+      return { type: 'del_slide', index: idx >= 0 ? idx : (op.atIndex as number || deck.slides.length - 1) }
+    }
+
+    case 'del_slide': {
+      // 逆：把删掉的页插回原位
+      const index = op.index as number
+      const deletedSlide = op.deletedSlide as Slide | undefined
+      if (deletedSlide) {
+        return { type: 'add_slide', atIndex: index, slide: deletedSlide }
+      }
+      // 没有 deletedSlide 信息（兼容），返回 no-op
+      return { type: 'replace_deck', deck: clone(deck) }
+    }
+
+    case 'move_slide': {
+      // 逆：from/to 反过来
+      return { type: 'move_slide', from: op.to as number, to: op.from as number }
+    }
+
+    case 'replace_slide': {
+      // 逆：换回原来的 slide
+      const index = op.index as number
+      const oldSlide = deck.slides[index] ? clone(deck.slides[index]) : undefined
+      if (oldSlide) {
+        return { type: 'replace_slide', index, slide: (op.oldSlide as Slide) || oldSlide }
+      }
+      return { type: 'replace_deck', deck: clone(deck) }
+    }
+
+    case 'set_slide_bg': {
+      // 逆：换回原来的背景
+      const index = op.index as number
+      const oldBg = deck.slides[index]?.background || 'bg'
+      return { type: 'set_slide_bg', index, bg: oldBg }
+    }
+
+    case 'add_element': {
+      // 逆：删除加的元素
+      return { type: 'del_element', slideIdx: op.slideIdx, elementId: (op.element as SlideElement).id }
+    }
+
+    case 'update_element': {
+      // 逆：把被改的字段恢复原值
+      const slideIdx = op.slideIdx as number
+      const elementId = op.elementId as string
+      const patch = op.patch as Record<string, unknown>
+      const el = findEl(deck, slideIdx, elementId)
+      if (!el) return { type: 'replace_deck', deck: clone(deck) }
+      // 构造反向 patch：取当前值
+      const backwardPatch: Record<string, unknown> = {}
+      if (patch.style) {
+        const oldStyle: Record<string, unknown> = {}
+        for (const k of Object.keys(patch.style as object)) {
+          oldStyle[k] = (el.style as Record<string, unknown>)[k]
+        }
+        backwardPatch.style = oldStyle
+      }
+      for (const k of Object.keys(patch)) {
+        if (k === 'style') continue
+        backwardPatch[k] = (el as unknown as Record<string, unknown>)[k]
+      }
+      return { type: 'update_element', slideIdx, elementId, patch: backwardPatch }
+    }
+
+    case 'del_element': {
+      // 逆：把删掉的元素加回去
+      const slideIdx = op.slideIdx as number
+      const deletedElement = op.deletedElement as SlideElement | undefined
+      if (deletedElement) {
+        return { type: 'add_element', slideIdx, element: deletedElement }
+      }
+      return { type: 'replace_deck', deck: clone(deck) }
+    }
+
+    case 'move_element_z': {
+      // 逆：方向反过来
+      return { type: 'move_element_z', slideIdx: op.slideIdx, elementId: op.elementId, dir: -(op.dir as number) }
+    }
+
+    case 'set_theme': {
+      // 逆：换回原来的主题
+      return { type: 'set_theme', theme: deck.theme }
+    }
+
+    case 'replace_deck': {
+      // 逆：换回整个旧 deck
+      return { type: 'replace_deck', deck: clone(deck) }
+    }
+
+    default:
+      return { type: 'replace_deck', deck: clone(deck) }
+  }
+}
diff --git a/src/core/store.ts b/src/core/store.ts
index a6f2d78..c992713 100644
--- a/src/core/store.ts
+++ b/src/core/store.ts
@@ -3,8 +3,9 @@
  * 由 store.js 迁移：用 Vue reactive 替代手写 pub/sub，组件自动追踪
  * ===================================================================== */
 import { reactive, computed } from 'vue'
-import type { AiCfg, Deck, LibItem, PageTemplate, Slide, SlideElement, ThemeKey } from './types'
+import type { AiCfg, Deck, LibItem, PageTemplate, Slide, SlideElement, ThemeKey, ChatMessage } from './types'
 import { DECK_VERSION, SAMPLE_DECK, createElement, themes, uid } from './sample'
+import { applyOp, invertOp, type Op, type HistoryEntry } from './op'
 
 /* ---------- localStorage 键 ---------- */
 const LS_KEY = 'u-ppt.deck.v1'
@@ -70,15 +71,17 @@ const BUILTIN_TEMPLATES: PageTemplate[] = [
   }
 ]
 
-/* ---------- 历史快照 ---------- */
-interface Snapshot { deck: Deck; index: number; sel: string | null }
+/* ---------- Op 历史栈（undo/redo 基于 Op 回滚） ---------- */
 const HIST_MAX = 40
-let hist: Snapshot[] = []
-let future: Snapshot[] = []
+let hist: HistoryEntry[] = []     // 过去的操作
+let future: HistoryEntry[] = []  // redo 栈
 let suppressHistory = false
 let touchKey: string | null = null
 let touchTimer: ReturnType<typeof setTimeout> | null = null
 
+/** 当前端的 client ID（为协同预留） */
+const CLIENT_ID = 'client-' + Math.random().toString(36).slice(2, 10)
+
 /* ---------- 响应式状态（单一数据源） ---------- */
 const state = reactive<{
   deck: Deck
@@ -173,20 +176,40 @@ export function resolveBg(key: string): string {
   return t[key] || '#ffffff'
 }
 
-/* ---------- 历史快照 ---------- */
-function pushHistory() {
-  if (suppressHistory) return
-  hist.push({ deck: clone(state.deck), index: state.currentIndex, sel: state.selectedId })
+/* ---------- 内部：执行 Op 并推入历史 ---------- */
+
+/** 执行一个 Op，计算逆 Op，推入历史栈。返回是否执行成功 */
+function execOp(op: Op, opts?: { coalesceKey?: string }): void {
+  if (suppressHistory) {
+    state.deck = applyOp(state.deck, op)
+    scheduleSave()
+    return
+  }
+  // 连续同类操作合并（如拖字号滑块）
+  if (opts?.coalesceKey && touchKey === opts.coalesceKey && hist.length > 0) {
+    // 合并：不推新历史，只执行 forward（已有的 backward 保持不变）
+    state.deck = applyOp(state.deck, op)
+    scheduleSave()
+    if (touchTimer) clearTimeout(touchTimer)
+    touchTimer = setTimeout(() => { touchKey = null }, 900)
+    return
+  }
+  // 计算逆 Op（在执行前）
+  const backward = invertOp(state.deck, op)
+  // 执行正向
+  state.deck = applyOp(state.deck, op)
+  // 推入历史
+  const entry: HistoryEntry = { forward: op, backward }
+  hist.push(entry)
   if (hist.length > HIST_MAX) hist.shift()
   future.length = 0
-}
-
-/** 连续「同一元素同一字段」的操作合并为一条历史（如拖字号滑块、连续敲字） */
-function touchHistory(key: string) {
-  if (suppressHistory) return
-  if (touchKey !== key) { pushHistory(); touchKey = key }
-  if (touchTimer) clearTimeout(touchTimer)
-  touchTimer = setTimeout(() => { touchKey = null }, 900)
+  // coalesce 逻辑
+  if (opts?.coalesceKey) {
+    touchKey = opts.coalesceKey
+    if (touchTimer) clearTimeout(touchTimer)
+    touchTimer = setTimeout(() => { touchKey = null }, 900)
+  }
+  scheduleSave()
 }
 
 /* ---------- 数据版本迁移（旧版数据补字段升级，不丢弃） ---------- */
@@ -269,101 +292,73 @@ function selectElement(id: string | null) { state.selectedId = id || null }
 
 /* ---------- 主题 ---------- */
 function setTheme(name: string) {
-  // 允许内置主题键与已存的自定义主题键
   if (!themes[name] && !getCustomThemes()[name]) return
-  pushHistory()
-  state.deck.theme = name
-  scheduleSave()
+  execOp({ type: 'set_theme', theme: name, clientId: CLIENT_ID, timestamp: Date.now() })
 }
 
 /* ---------- 幻灯片 CRUD ---------- */
 function addSlide(atIndex?: number) {
-  pushHistory()
   const s: Slide = { id: uid('s'), background: 'bg', elements: [] }
   const idx = atIndex != null ? atIndex + 1 : state.deck.slides.length
-  state.deck.slides.splice(idx, 0, s)
+  execOp({ type: 'add_slide', atIndex: idx, slide: s, clientId: CLIENT_ID, timestamp: Date.now() })
   state.currentIndex = idx
   state.selectedId = null
-  scheduleSave()
   return s
 }
 
 function dupSlide() {
-  pushHistory()
   const cur = currentSlide.value; if (!cur) return
   const copy = clone(cur); copy.id = uid('s')
   copy.elements.forEach(e => { e.id = uid('el') })
-  state.deck.slides.splice(state.currentIndex + 1, 0, copy)
-  state.currentIndex++
+  const idx = state.currentIndex + 1
+  execOp({ type: 'add_slide', atIndex: idx, slide: copy, clientId: CLIENT_ID, timestamp: Date.now() })
+  state.currentIndex = idx
   state.selectedId = null
-  scheduleSave()
 }
 
 function delSlide(i?: number): boolean {
   if (state.deck.slides.length <= 1) return false
-  pushHistory()
   const idx = i != null ? i : state.currentIndex
-  state.deck.slides.splice(idx, 1)
+  const deletedSlide = clone(state.deck.slides[idx])
+  execOp({ type: 'del_slide', index: idx, deletedSlide, clientId: CLIENT_ID, timestamp: Date.now() })
   if (state.currentIndex >= state.deck.slides.length) state.currentIndex = state.deck.slides.length - 1
   state.selectedId = null
-  scheduleSave()
   return true
 }
 
 function moveSlide(from: number, to: number) {
   if (from === to || from < 0 || to < 0) return
-  const arr = state.deck.slides
-  if (to >= arr.length) return
-  pushHistory()
-  const item = arr.splice(from, 1)[0]
-  arr.splice(to, 0, item)
+  if (to >= state.deck.slides.length) return
+  execOp({ type: 'move_slide', from, to, clientId: CLIENT_ID, timestamp: Date.now() })
   state.currentIndex = to
-  scheduleSave()
 }
 
 function setSlideBackground(bg: string) {
-  pushHistory()
-  currentSlide.value.background = bg as Slide['background']
-  scheduleSave()
+  execOp({ type: 'set_slide_bg', index: state.currentIndex, bg: bg as Slide['background'], clientId: CLIENT_ID, timestamp: Date.now() })
 }
 
 /* ---------- 元素 CRUD ---------- */
 function addElement(type: SlideElement['type'], over?: Parameters<typeof createElement>[1]) {
-  pushHistory()
   const el = createElement(type, over)
-  currentSlide.value.elements.push(el)
+  execOp({ type: 'add_element', slideIdx: state.currentIndex, element: el, clientId: CLIENT_ID, timestamp: Date.now() })
   state.selectedId = el.id
-  scheduleSave()
   return el
 }
 
 function updateElement(id: string, patch: Partial<SlideElement> & { style?: Record<string, unknown> }) {
-  const key = id + ':' + (patch.style ? Object.keys(patch.style).sort().join(',') : Object.keys(patch).sort().join(','))
-  touchHistory(key)
-  const el = findElement(id); if (!el) return
-  if (patch.style) { Object.assign(el.style, patch.style) }
-  const rest = { ...patch }; delete (rest as Record<string, unknown>).style
-  Object.assign(el, rest)
-  scheduleSave()
+  const coalesceKey = id + ':' + (patch.style ? Object.keys(patch.style).sort().join(',') : Object.keys(patch).sort().join(','))
+  execOp({ type: 'update_element', slideIdx: state.currentIndex, elementId: id, patch, clientId: CLIENT_ID, timestamp: Date.now() }, { coalesceKey })
 }
 
 function delElement(id: string) {
-  pushHistory()
-  const s = currentSlide.value
-  s.elements = s.elements.filter(e => e.id !== id)
+  const el = findElement(id)
+  const deletedElement = el ? clone(el) : undefined
+  execOp({ type: 'del_element', slideIdx: state.currentIndex, elementId: id, deletedElement, clientId: CLIENT_ID, timestamp: Date.now() })
   if (state.selectedId === id) state.selectedId = null
-  scheduleSave()
 }
 
 function moveElementZ(id: string, dir: number) {
-  pushHistory()
-  const s = currentSlide.value
-  const i = s.elements.findIndex(e => e.id === id)
-  if (i < 0) return
-  const j = dir > 0 ? i + 1 : i - 1
-  if (j < 0 || j >= s.elements.length) return
-  const tmp = s.elements[i]; s.elements[i] = s.elements[j]; s.elements[j] = tmp
-  scheduleSave()
+  execOp({ type: 'move_element_z', slideIdx: state.currentIndex, elementId: id, dir, clientId: CLIENT_ID, timestamp: Date.now() })
 }
 
 function findElement(id: string): SlideElement | null {
@@ -371,91 +366,83 @@ function findElement(id: string): SlideElement | null {
   return s.elements.find(e => e.id === id) || null
 }
 
-/* ---------- undo / redo ---------- */
+/* ---------- undo / redo（基于 Op 回滚） ---------- */
 function undo(): boolean {
   if (!hist.length) return false
-  future.push({ deck: clone(state.deck), index: state.currentIndex, sel: state.selectedId })
-  const prev = hist.pop()!
+  const entry = hist.pop()!
   suppressHistory = true
-  state.deck = prev.deck
-  state.currentIndex = Math.min(prev.index, state.deck.slides.length - 1)
-  state.selectedId = prev.sel
+  state.deck = applyOp(state.deck, entry.backward)
   suppressHistory = false
+  future.push(entry)
   scheduleSave()
   return true
 }
 
 function redo(): boolean {
   if (!future.length) return false
-  hist.push({ deck: clone(state.deck), index: state.currentIndex, sel: state.selectedId })
-  const nxt = future.pop()!
+  const entry = future.pop()!
   suppressHistory = true
-  state.deck = nxt.deck
-  state.currentIndex = Math.min(nxt.index, state.deck.slides.length - 1)
-  state.selectedId = nxt.sel
+  state.deck = applyOp(state.deck, entry.forward)
   suppressHistory = false
+  hist.push(entry)
   scheduleSave()
   return true
 }
 
 /* ---------- 整体替换（AI 生成 / 导入 / 重置用） ---------- */
 function replaceDeck(newDeck: Deck | Record<string, unknown>, opts?: { keepHistory?: boolean; newChat?: boolean }) {
-  if (!opts?.keepHistory) pushHistory()
   // 自动备份：newChat=true 时说明是生成整套/重置等“覆盖性操作”，把当前 deck 存入 .bak
   if (opts?.newChat && state.deck?.slides?.length) {
     try { localStorage.setItem(LS_KEY + '.bak', JSON.stringify(state.deck)) } catch (e) {}
   }
-  suppressHistory = true
   let d = newDeck as Deck
   if (!d || typeof d !== 'object') d = {} as Deck
-  d.v = DECK_VERSION   // 维护版本号
-  // 健壮性：损坏/空数据兜底为一页空白，避免下游 forEach 崩溃
+  d.v = DECK_VERSION
   if (!Array.isArray(d.slides) || !d.slides.length) {
     d.slides = [{ id: uid('s'), background: 'bg', elements: [] }]
   }
-  // 会话 ID 绑定：newChat=true 开新会话；否则沿用 deck 自带的 chatId（文库加载时）；都没有则生成新的
   if (opts?.newChat || !d.chatId) {
     d.chatId = newChatId()
   }
-  state.deck = d
+  if (opts?.keepHistory) {
+    suppressHistory = true
+    state.deck = d
+    suppressHistory = false
+    scheduleSave()
+  } else {
+    execOp({ type: 'replace_deck', deck: d, clientId: CLIENT_ID, timestamp: Date.now() })
+  }
   state.activeLibId = null
   state.currentIndex = Math.min(state.currentIndex, d.slides.length - 1)
   if (state.currentIndex < 0) state.currentIndex = 0
   state.selectedId = null
-  suppressHistory = false
-  scheduleSave()
 }
 
 function replaceSlide(index: number, newSlide: Slide) {
-  pushHistory()
-  newSlide.id = state.deck.slides[index] ? state.deck.slides[index].id : uid('s')
   newSlide.elements = newSlide.elements || []
   newSlide.elements.forEach(e => { if (!e.id) e.id = uid('el') })
-  state.deck.slides[index] = newSlide
+  const oldSlide = state.deck.slides[index] ? clone(state.deck.slides[index]) : undefined
+  execOp({ type: 'replace_slide', index, slide: newSlide, oldSlide, clientId: CLIENT_ID, timestamp: Date.now() })
   state.selectedId = null
-  scheduleSave()
 }
 
 function appendSlide(newSlide: Slide) {
-  pushHistory()
   newSlide.id = uid('s')
   newSlide.elements = newSlide.elements || []
   newSlide.elements.forEach(e => { if (!e.id) e.id = uid('el') })
-  state.deck.slides.push(newSlide)
-  state.currentIndex = state.deck.slides.length - 1
+  const idx = state.deck.slides.length
+  execOp({ type: 'add_slide', atIndex: idx, slide: newSlide, clientId: CLIENT_ID, timestamp: Date.now() })
+  state.currentIndex = idx
   state.selectedId = null
-  scheduleSave()
 }
 
 function insertSlideAt(index: number, newSlide: Slide) {
-  pushHistory()
   newSlide.id = uid('s')
   newSlide.elements = newSlide.elements || []
   newSlide.elements.forEach(e => { if (!e.id) e.id = uid('el') })
-  state.deck.slides.splice(index, 0, newSlide)
+  execOp({ type: 'add_slide', atIndex: index, slide: newSlide, clientId: CLIENT_ID, timestamp: Date.now() })
   state.currentIndex = index
   state.selectedId = null
-  scheduleSave()
 }
 
 function reset() {
@@ -517,14 +504,12 @@ function saveCustomTheme(t: import('./types').Theme): string {
 
 /** 应用一个主题（内置 key 或自定义对象）到当前 deck */
 function applyTheme(nameOrObj: string | import('./types').Theme) {
-  pushHistory()
   if (typeof nameOrObj === 'string') {
-    state.deck.theme = nameOrObj
+    execOp({ type: 'set_theme', theme: nameOrObj, clientId: CLIENT_ID, timestamp: Date.now() })
   } else {
     const key = saveCustomTheme(nameOrObj)
-    state.deck.theme = key
+    execOp({ type: 'set_theme', theme: key, clientId: CLIENT_ID, timestamp: Date.now() })
   }
-  scheduleSave()
 }
 
 /* ---------- 页面模板（版式复用） ---------- */
@@ -569,20 +554,19 @@ function saveCurrentAsTemplate(name: string): PageTemplate {
 function addSlideFromTemplate(tplId: string): boolean {
   const tpl = getTemplates().find(t => t.id === tplId)
   if (!tpl) return false
-  pushHistory()
   const newSlide: Slide = {
     id: uid('s'),
     background: tpl.background,
     elements: clone(tpl.elements).map(e => ({ ...e, id: uid('el') }))
   }
   const idx = state.currentIndex + 1
-  state.deck.slides.splice(idx, 0, newSlide)
+  execOp({ type: 'add_slide', atIndex: idx, slide: newSlide, clientId: CLIENT_ID, timestamp: Date.now() })
   state.currentIndex = idx
   state.selectedId = null
-  scheduleSave()
   return true
 }
 
+/* ---------- 删除用户模板 ---------- */
 /** 删除用户模板 */
 function deleteTemplate(tplId: string) {
   const user = getUserTemplates().filter(t => t.id !== tplId)
@@ -661,7 +645,6 @@ function newBlankDeck() {
 }
 
 /* ---------- 会话管理（按 chatId 隔离） ---------- */
-import type { ChatMessage } from './types'
 
 function newChatId(): string {
   return 'chat-' + Date.now() + '-' + Math.random().toString(36).slice(2, 8)