diff --git a/docs/design-system.md b/docs/design-system.md
index 4c28a54533..5d0f74ebad 100644
--- a/docs/design-system.md
+++ b/docs/design-system.md
@@ -618,7 +618,7 @@
 | `useDcFormSubmit` | `@dc-ui/components/form` | 提交状态机 composable：`{ status, run, reset }`；`run(fn)` 驱动 idle→submitting→success/error，成功/失败按时长自动回退 |
 | `useDcForm` | `@dc-ui/components/form` | 读取 `DcForm` 注入上下文（`DC_FORM_INJECTION_KEY`），供自定义提交控件使用 |
 | `DcBadge` | `@dc-ui/components/badge` | shadcn Badge 语义化封装：default/secondary/outline/destructive 透传 + `success`/`warning`/`danger`/`active`/`neutral`（带 dark 变体，与 DcStatusPill 色系一致） |
-| `DcCopyButton` | `@dc-ui/components/copy-button` | 复制按钮：`copy-text` + `navigator.clipboard`，成功图标短暂变 ✅（`success-duration`）；`label`/`show-toast` 可选；`@copied`/`@error` 事件 |
+| `DcCopyButton` | `@dc-ui/components/button` | 复制按钮：复用 `DcButton` 契约，`variant` 缺省 `ghost`；`copy-text` 必填触发复制（`useClipboard`），成功图标切 ✅（1200ms 自动回退、色值变 emerald）；`@copied`/`@error` 事件；`label`/`tooltip` 提供可访问名，`copy-text` 兜底 |
 | `DcDropdownActionItem` | `@dc-ui/components/dropdown-action-item` | 菜单动作项：`icon`/`label`/`danger`（destructive 变体）/`disabled`/`inset` + `@select`，收敛 `Icon mr-2 + span` 散写 |
 | `DcFormActions` | `@dc-ui/components/form-actions` | 表单底部操作组：「取消 + 提交（DcSubmitButton）」+ 中间插槽；`submit-status`/`cancel-label`/`submit-label`/`danger-submit` |
 
@@ -635,10 +635,11 @@
 - **tooltip 补齐边界**：只为可操作的 icon-only 控件补齐；文字按钮、纯展示 Icon、以及说明型 Switch/Checkbox/链接提示维持原行为，不为统一形式强行增加 tooltip。
 - 新增 dc-ui 组件需先证明既有组件无法覆盖；在本文档登记聚合后的完整契约，并符合 §20/§21 的密度与 token 规则。
 
-### 22.3 迁移状态（2026-08 批次，未提交）
+### 22.3 迁移状态（2026-08 批次）
 
 - **`DcButton` 聚合**：`DcIconButton` 已并入并删除（13 处调用迁入）；手写 Tooltip+按钮迁移 10 文件 30 处（MessageToolbar 12 / WindowSideBar 8 / ChatStatusBar 2 / ModelConfigItem / MessageBlockImage / MessageBlockToolCallImagePreview / SkillsIndicator / SkillsPanel / ChatInputToolbar 4）。`DcButton` 已补齐 tooltip 定位、延迟、content class 与 keyboard-focus 参数，保留复杂提示契约。
+- **`DcCopyButton` 归位**：由 `@dc-ui/components/copy-button` 并入 `@dc-ui/components/button`（旧目录删除），消费方（MessageToolbar / ArtifactBlock / CodeArtifact / McpJsonViewer / McpServers / TraceDialog / MessageBlockToolCall）全部经 `copy-text` 传入复制内容，MessageToolbar 增加 `copy-text` prop。
 - **`DcConfirmDialog`**：迁移 5 文件 7 框（ChatPage / ModelConfigDialog ×2 / KnowledgeFileItem ×2 / SkillInstallDialog / SkillDetailDialog ×2）+ ChatPage.test.ts 适配。
 - **`DcEmpty`**：迁移 10 文件 12 处空态（含 MemoryEmptyState 用 `#action` 插槽，组件接口不变）。
 - **`DcSectionCard`** 4 文件 11 卡（MemoryDiagnosticsPanel / MemoryDirectivesPanel / MemoryConfigInlinePanel / OfficialPluginDetailPage）；**`DcStatusPill`** 2 文件（RemoteSettings 5 渠道 / AcpDebugDialog）；**`DcInlineError`** 12 文件（McpServerForm 5 处等）。
-- **有意保留（记录在案）**：WindowSideBar remote-control（多行 tooltip）、WindowSideBarSessionItem pin/delete（依赖 scoped CSS）、MessageDialog / UpdateTaskCheckDialog（动态多按钮）、SettingsLeaveGuardDialog（路由守卫）、DataSettings 单按钮错误弹窗、desc-only 空态提示、带重试按钮的错误横幅。
\ No newline at end of file
+- **有意保留（记录在案）**：WindowSideBar remote-control（多行 tooltip）、WindowSideBarSessionItem pin/delete（依赖 scoped CSS）、MessageDialog / UpdateTaskCheckDialog（动态多按钮）、SettingsLeaveGuardDialog（路由守卫）、DataSettings 单按钮错误弹窗、desc-only 空态提示、带重试按钮的错误横幅。
diff --git a/src/dc-ui/components/button/DcButton.vue b/src/dc-ui/components/button/DcButton.vue
index 7f5f5c7a48..23d17bae8c 100644
--- a/src/dc-ui/components/button/DcButton.vue
+++ b/src/dc-ui/components/button/DcButton.vue
@@ -1,6 +1,4 @@
 <script setup lang="ts">
-import type { PrimitiveProps } from 'reka-ui'
-import type { HTMLAttributes } from 'vue'
 import { computed, useSlots } from 'vue'
 import { Icon } from '@iconify/vue'
 import { Primitive } from 'reka-ui'
@@ -12,32 +10,9 @@ import {
   TooltipProvider,
   TooltipTrigger
 } from '@shadcn/components/ui/tooltip'
-import { dcButtonVariants, type DcButtonVariants } from './index'
+import { dcButtonVariants, DcButtonProps } from './props'
 
-type DcIconSize = '3' | '3.5' | '4'
-type DcTooltipSide = 'top' | 'bottom' | 'left' | 'right'
-
-interface Props extends PrimitiveProps {
-  variant?: DcButtonVariants['variant']
-  size?: DcButtonVariants['size']
-  icon?: string
-  iconSize?: DcIconSize
-  iconClass?: HTMLAttributes['class']
-  loading?: boolean
-  disabled?: boolean
-  active?: boolean
-  /** Visible tooltip. `label` alone only provides the accessible name. */
-  tooltip?: string
-  tooltipSide?: DcTooltipSide
-  tooltipSideOffset?: number
-  tooltipDelayDuration?: number
-  tooltipContentClass?: HTMLAttributes['class']
-  tooltipIgnoreNonKeyboardFocus?: boolean
-  label?: string
-  class?: HTMLAttributes['class']
-}
-
-const props = withDefaults(defineProps<Props>(), {
+const props = withDefaults(defineProps<DcButtonProps>(), {
   as: 'button',
   iconSize: '4',
   disabled: false,
@@ -98,7 +73,7 @@ if (import.meta.env.DEV && !accessibleName.value && isIconOnly.value && !slots.d
           :class="buttonClass"
         >
           <Spinner v-if="loading" data-icon="inline-start" :class="iconSizeClass" />
-          <Icon v-else-if="icon" :icon="icon" :class="cn(iconSizeClass, iconClass)" />
+          <Icon v-else-if="icon" :key="icon" :icon="icon" :class="cn(iconSizeClass, iconClass)" />
           <slot />
         </Primitive>
       </TooltipTrigger>
@@ -121,7 +96,7 @@ if (import.meta.env.DEV && !accessibleName.value && isIconOnly.value && !slots.d
       :class="buttonClass"
     >
       <Spinner v-if="loading" data-icon="inline-start" :class="iconSizeClass" />
-      <Icon v-else-if="icon" :icon="icon" :class="cn(iconSizeClass, iconClass)" />
+      <Icon v-else-if="icon" :key="icon" :icon="icon" :class="cn(iconSizeClass, iconClass)" />
       <slot />
     </Primitive>
   </TooltipProvider>
diff --git a/src/dc-ui/components/button/DcCopyButton.vue b/src/dc-ui/components/button/DcCopyButton.vue
new file mode 100644
index 0000000000..e508e8f3da
--- /dev/null
+++ b/src/dc-ui/components/button/DcCopyButton.vue
@@ -0,0 +1,98 @@
+<script lang="ts">
+import { computed, defineComponent, h, onUnmounted, ref, type PropType } from 'vue'
+import { useClipboard } from '@vueuse/core'
+import { cn } from '@shadcn/lib/utils'
+import { type DcButtonProps } from './props'
+import DcButton from './DcButton.vue'
+
+interface DcCopyButtonProps extends DcButtonProps {
+  copyText: string
+}
+
+type ClickHandler = (event: MouseEvent) => void
+
+export default defineComponent({
+  name: 'DcCopyButton',
+  inheritAttrs: false,
+  props: {
+    copyText: {
+      type: String,
+      required: true
+    },
+    variant: {
+      type: String as PropType<DcCopyButtonProps['variant']>,
+      default: 'ghost'
+    }
+  },
+  emits: {
+    copied: () => true,
+    error: (_error: unknown) => true
+  },
+  setup(props, { attrs, emit, slots }) {
+    const copied = ref(false)
+    let timer: ReturnType<typeof setTimeout> | undefined
+    const { copy } = useClipboard()
+    const icon = computed(() => (copied.value ? 'lucide:check' : 'lucide:copy'))
+
+    const copyText = async () => {
+      try {
+        await copy(props.copyText)
+        copied.value = true
+        clearTimeout(timer)
+        timer = setTimeout(() => {
+          copied.value = false
+        }, 1200)
+        emit('copied')
+      } catch (error) {
+        console.error('[DcCopyButton] Failed to copy', error)
+        emit('error', error)
+      }
+    }
+
+    const callClickHandler = (handler: unknown, event: MouseEvent) => {
+      if (Array.isArray(handler)) {
+        handler.forEach((item) => callClickHandler(item, event))
+        return
+      }
+      if (typeof handler === 'function') {
+        const clickHandler = handler as ClickHandler
+        clickHandler(event)
+      }
+    }
+
+    onUnmounted(() => clearTimeout(timer))
+
+    return () => {
+      const inheritedAttrs = attrs as Partial<DcButtonProps> & Record<string, unknown>
+      const { copyText: _copyText, ...buttonProps } = props
+      const accessibleName = inheritedAttrs.label ?? inheritedAttrs.tooltip ?? _copyText
+      const inheritedClick = inheritedAttrs.onClick
+
+      return h(
+        DcButton,
+        {
+          ...inheritedAttrs,
+          ...buttonProps,
+          key: icon.value,
+          icon: icon.value,
+          iconClass: cn(
+            inheritedAttrs.iconClass,
+            copied.value && 'animate-in zoom-in-75 duration-200'
+          ),
+          label: accessibleName,
+          class: cn(
+            'shrink-0',
+            copied.value ? 'text-emerald-600 dark:text-emerald-400' : '',
+            inheritedAttrs.class
+          ),
+          onClick: (event: MouseEvent) => {
+            callClickHandler(inheritedClick, event)
+            void copyText()
+          }
+        },
+        slots
+      )
+    }
+  }
+})
+</script>
diff --git a/src/dc-ui/components/button/index.ts b/src/dc-ui/components/button/index.ts
index 27c43dc106..45a7628e0b 100644
--- a/src/dc-ui/components/button/index.ts
+++ b/src/dc-ui/components/button/index.ts
@@ -1,38 +1,3 @@
-import type { VariantProps } from 'class-variance-authority'
-import { cva } from 'class-variance-authority'
-
 export { default as DcButton } from './DcButton.vue'
-
-export const dcButtonVariants = cva(
-  'inline-flex items-center justify-center whitespace-nowrap rounded-md text-sm font-medium transition-[color,background-color,border-color,scale] duration-[var(--dc-motion-fast)] ease-[var(--dc-ease-out-soft)] active:scale-[0.97] motion-reduce:active:scale-100 disabled:pointer-events-none disabled:opacity-50 [&_svg]:pointer-events-none [&_svg:not([class*="size-"])]:size-4 [&_svg]:shrink-0 shrink-0 outline-none focus-visible:border-ring focus-visible:ring-ring/50 focus-visible:ring-[3px]',
-  {
-    variants: {
-      variant: {
-        default: 'bg-primary text-primary-foreground shadow-xs hover:bg-primary/90',
-        destructive:
-          'bg-destructive text-white shadow-xs hover:bg-destructive/90 focus-visible:ring-destructive/20 dark:focus-visible:ring-destructive/40 dark:bg-destructive/60',
-        outline:
-          'border bg-background shadow-xs hover:bg-accent hover:text-accent-foreground dark:bg-input/30 dark:border-input dark:hover:bg-input/50',
-        secondary: 'bg-secondary text-secondary-foreground shadow-xs hover:bg-secondary/80',
-        ghost: 'hover:bg-accent hover:text-accent-foreground dark:hover:bg-accent/50',
-        link: 'text-primary underline-offset-4 hover:underline'
-      },
-      size: {
-        default: 'h-9 gap-2 px-4 py-2 has-[>svg]:px-3',
-        sm: 'h-8 gap-1.5 rounded-md px-3 has-[>svg]:px-2.5',
-        xs: 'h-7 gap-1.5 rounded-md px-2.5 text-xs has-[>svg]:px-2',
-        lg: 'h-10 gap-2 rounded-md px-6 has-[>svg]:px-4',
-        icon: 'size-8',
-        'icon-sm': 'size-7',
-        'icon-xs': 'size-6',
-        'icon-lg': 'size-10'
-      }
-    },
-    defaultVariants: {
-      variant: 'default',
-      size: 'default'
-    }
-  }
-)
-
-export type DcButtonVariants = VariantProps<typeof dcButtonVariants>
+export { default as DcCopyButton } from './DcCopyButton.vue'
+export * from './props'
diff --git a/src/dc-ui/components/button/props.ts b/src/dc-ui/components/button/props.ts
new file mode 100644
index 0000000000..3e54df4b21
--- /dev/null
+++ b/src/dc-ui/components/button/props.ts
@@ -0,0 +1,62 @@
+import type { PrimitiveProps } from 'reka-ui'
+import type { HTMLAttributes } from 'vue'
+
+export interface DcButtonProps extends PrimitiveProps {
+  variant?: DcButtonVariants['variant']
+  size?: DcButtonVariants['size']
+  icon?: string
+  iconSize?: DcIconSize
+  iconClass?: HTMLAttributes['class']
+  loading?: boolean
+  disabled?: boolean
+  active?: boolean
+  /** Visible tooltip. `label` alone only provides the accessible name. */
+  tooltip?: string
+  tooltipSide?: DcTooltipSide
+  tooltipSideOffset?: number
+  tooltipDelayDuration?: number
+  tooltipContentClass?: HTMLAttributes['class']
+  tooltipIgnoreNonKeyboardFocus?: boolean
+  label?: string
+  class?: HTMLAttributes['class']
+}
+
+import type { VariantProps } from 'class-variance-authority'
+import { cva } from 'class-variance-authority'
+
+type DcIconSize = '3' | '3.5' | '4'
+type DcTooltipSide = 'top' | 'bottom' | 'left' | 'right'
+
+export const dcButtonVariants = cva(
+  'inline-flex items-center justify-center whitespace-nowrap rounded-md text-sm font-medium transition-[color,background-color,border-color,scale] duration-[var(--dc-motion-fast)] ease-[var(--dc-ease-out-soft)] active:scale-[0.97] motion-reduce:active:scale-100 disabled:pointer-events-none disabled:opacity-50 [&_svg]:pointer-events-none [&_svg:not([class*="size-"])]:size-4 [&_svg]:shrink-0 shrink-0 outline-none focus-visible:border-ring focus-visible:ring-ring/50 focus-visible:ring-[3px]',
+  {
+    variants: {
+      variant: {
+        default: 'bg-primary text-primary-foreground shadow-xs hover:bg-primary/90',
+        destructive:
+          'bg-destructive text-white shadow-xs hover:bg-destructive/90 focus-visible:ring-destructive/20 dark:focus-visible:ring-destructive/40 dark:bg-destructive/60',
+        outline:
+          'border bg-background shadow-xs hover:bg-accent hover:text-accent-foreground dark:bg-input/30 dark:border-input dark:hover:bg-input/50',
+        secondary: 'bg-secondary text-secondary-foreground shadow-xs hover:bg-secondary/80',
+        ghost: 'hover:bg-accent hover:text-accent-foreground dark:hover:bg-accent/50',
+        link: 'text-primary underline-offset-4 hover:underline'
+      },
+      size: {
+        default: 'h-9 gap-2 px-4 py-2 has-[>svg]:px-3',
+        sm: 'h-8 gap-1.5 rounded-md px-3 has-[>svg]:px-2.5',
+        xs: 'h-7 gap-1.5 rounded-md px-2.5 text-xs has-[>svg]:px-2',
+        lg: 'h-10 gap-2 rounded-md px-6 has-[>svg]:px-4',
+        icon: 'size-8',
+        'icon-sm': 'size-7',
+        'icon-xs': 'size-6',
+        'icon-lg': 'size-10'
+      }
+    },
+    defaultVariants: {
+      variant: 'default',
+      size: 'default'
+    }
+  }
+)
+
+export type DcButtonVariants = VariantProps<typeof dcButtonVariants>
diff --git a/src/dc-ui/components/copy-button/DcCopyButton.vue b/src/dc-ui/components/copy-button/DcCopyButton.vue
deleted file mode 100644
index 296dd1ef9a..0000000000
--- a/src/dc-ui/components/copy-button/DcCopyButton.vue
+++ /dev/null
@@ -1,142 +0,0 @@
-<script setup lang="ts">
-import type { HTMLAttributes } from 'vue'
-import { computed, onUnmounted, ref } from 'vue'
-import { useI18n } from 'vue-i18n'
-import { DcButton } from '@dc-ui/components/button'
-import { notifyRenderer } from '@renderer-notifications/rendererNotificationPort'
-import {
-  Tooltip,
-  TooltipContent,
-  TooltipProvider,
-  TooltipTrigger
-} from '@shadcn/components/ui/tooltip'
-import { cn } from '@shadcn/lib/utils'
-
-type DcTooltipSide = 'top' | 'bottom' | 'left' | 'right'
-
-interface Props {
-  /** 要复制的内容；缺省时组件不执行复制，由调用方通过 slot 自定义或事件处理 */
-  copyText?: string
-  /** 是否带文字标签（默认 icon-only） */
-  label?: string
-  size?: 'default' | 'sm' | 'xs'
-  iconSize?: '3' | '3.5' | '4'
-  variant?: 'default' | 'outline' | 'secondary' | 'ghost' | 'destructive' | 'link'
-  /** 复制成功时是否弹 toast（默认只显示按钮 ✅） */
-  showToast?: boolean
-  successDuration?: number
-  disabled?: boolean
-  /** 显式 tooltip；不复用 label，避免文字按钮意外出现 tooltip */
-  tooltip?: string
-  tooltipSide?: DcTooltipSide
-  tooltipSideOffset?: number
-  tooltipDelayDuration?: number
-  tooltipContentClass?: HTMLAttributes['class']
-  tooltipIgnoreNonKeyboardFocus?: boolean
-  class?: HTMLAttributes['class']
-}
-
-const props = withDefaults(defineProps<Props>(), {
-  variant: 'ghost',
-  showToast: false,
-  successDuration: 1500,
-  tooltipSide: 'top',
-  tooltipSideOffset: 4,
-  tooltipIgnoreNonKeyboardFocus: false
-})
-
-defineOptions({
-  inheritAttrs: false
-})
-
-const emit = defineEmits<{
-  (e: 'copied'): void
-  (e: 'error', error: unknown): void
-}>()
-
-const { t } = useI18n()
-const copied = ref(false)
-let timer: ReturnType<typeof setTimeout> | undefined
-
-const copy = async () => {
-  if (!props.copyText) return
-  try {
-    await navigator.clipboard.writeText(props.copyText)
-    copied.value = true
-    clearTimeout(timer)
-    timer = setTimeout(() => {
-      copied.value = false
-    }, props.successDuration)
-    if (props.showToast) {
-      notifyRenderer({
-        kind: 'success',
-        code: 'common.copy.succeeded',
-        title: t('common.copied')
-      })
-    }
-    emit('copied')
-  } catch (error) {
-    console.error('[DcCopyButton] Failed to copy', error)
-    emit('error', error)
-    if (props.showToast) {
-      notifyRenderer({
-        kind: 'error',
-        code: 'common.copy.failed',
-        title: t('common.copyFailed')
-      })
-    }
-  }
-}
-
-onUnmounted(() => clearTimeout(timer))
-
-const icon = computed(() => (copied.value ? 'lucide:check' : 'lucide:copy'))
-const accessibleName = computed(() => props.label ?? props.tooltip)
-</script>
-
-<template>
-  <TooltipProvider
-    v-if="tooltip"
-    :delay-duration="tooltipDelayDuration"
-    :ignore-non-keyboard-focus="tooltipIgnoreNonKeyboardFocus"
-  >
-    <Tooltip :delay-duration="tooltipDelayDuration">
-      <TooltipTrigger as-child>
-        <DcButton
-          v-bind="$attrs"
-          :variant="variant"
-          :size="size"
-          :icon="icon"
-          :icon-size="iconSize"
-          :disabled="disabled"
-          :label="accessibleName"
-          :class="cn('shrink-0', copied && 'text-emerald-600 dark:text-emerald-400', props.class)"
-          @click="copy"
-        >
-          <slot>{{ label }}</slot>
-        </DcButton>
-      </TooltipTrigger>
-      <TooltipContent
-        :side="tooltipSide"
-        :side-offset="tooltipSideOffset"
-        :class="tooltipContentClass"
-      >
-        {{ tooltip }}
-      </TooltipContent>
-    </Tooltip>
-  </TooltipProvider>
-  <DcButton
-    v-else
-    v-bind="$attrs"
-    :variant="variant"
-    :size="size"
-    :icon="icon"
-    :icon-size="iconSize"
-    :disabled="disabled"
-    :label="accessibleName"
-    :class="cn('shrink-0', copied && 'text-emerald-600 dark:text-emerald-400', props.class)"
-    @click="copy"
-  >
-    <slot>{{ label }}</slot>
-  </DcButton>
-</template>
diff --git a/src/dc-ui/components/copy-button/index.ts b/src/dc-ui/components/copy-button/index.ts
deleted file mode 100644
index ef90f141d8..0000000000
--- a/src/dc-ui/components/copy-button/index.ts
+++ /dev/null
@@ -1 +0,0 @@
-export { default as DcCopyButton } from './DcCopyButton.vue'
diff --git a/src/dc-ui/components/index.ts b/src/dc-ui/components/index.ts
new file mode 100644
index 0000000000..723978ff93
--- /dev/null
+++ b/src/dc-ui/components/index.ts
@@ -0,0 +1,16 @@
+export * from './button'
+export * from './status-pill'
+export * from './confirm-dialog'
+export * from './toggle-row'
+export * from './empty'
+export * from './skeleton'
+export * from './toast'
+export * from './tooltip'
+export * from './sheet-panel'
+export * from './popover'
+export * from './section-card'
+export * from './inline-error'
+export * from './form'
+export * from './badge'
+export * from './dropdown-action-item'
+export * from './form-actions'
diff --git a/src/dc-ui/components/toggle-row/DcToggleRow.vue b/src/dc-ui/components/toggle-row/DcToggleRow.vue
index 803aaf6459..6bb45a807c 100644
--- a/src/dc-ui/components/toggle-row/DcToggleRow.vue
+++ b/src/dc-ui/components/toggle-row/DcToggleRow.vue
@@ -35,10 +35,13 @@ const handleChecked = (value: boolean | 'indeterminate') => {
 <template>
   <div
     :class="
-      cn('flex items-center gap-3', description ? 'flex-col items-start gap-1.5 py-1' : 'h-10')
+      cn(
+        'w-full flex items-center gap-3',
+        description ? 'flex-col items-start gap-1.5 py-1' : 'h-10'
+      )
     "
   >
-    <div class="flex min-w-0 flex-1 items-center gap-3">
+    <div class="flex min-w-0 w-full flex-1 items-center gap-3">
       <Icon v-if="icon" :icon="icon" class="size-4 shrink-0 text-muted-foreground" />
       <Label
         :for="id"
diff --git a/src/dc-ui/index.ts b/src/dc-ui/index.ts
index 6466658904..cb64ac1b52 100644
--- a/src/dc-ui/index.ts
+++ b/src/dc-ui/index.ts
@@ -1,17 +1 @@
-export * from './components/button'
-export * from './components/status-pill'
-export * from './components/confirm-dialog'
-export * from './components/toggle-row'
-export * from './components/empty'
-export * from './components/skeleton'
-export * from './components/toast'
-export * from './components/tooltip'
-export * from './components/sheet-panel'
-export * from './components/popover'
-export * from './components/section-card'
-export * from './components/inline-error'
-export * from './components/form'
-export * from './components/badge'
-export * from './components/copy-button'
-export * from './components/dropdown-action-item'
-export * from './components/form-actions'
+export * from './components'
diff --git a/src/renderer/src/components/artifacts/ArtifactBlock.vue b/src/renderer/src/components/artifacts/ArtifactBlock.vue
index 07fbd4ecd9..18a87c5462 100644
--- a/src/renderer/src/components/artifacts/ArtifactBlock.vue
+++ b/src/renderer/src/components/artifacts/ArtifactBlock.vue
@@ -21,7 +21,7 @@
 
 <script setup lang="ts">
 import { computed } from 'vue'
-import { DcCopyButton } from '@dc-ui/components/copy-button'
+import { DcCopyButton } from '@dc-ui/components'
 import CodeArtifact from './CodeArtifact.vue'
 import MarkdownArtifact from './MarkdownArtifact.vue'
 import HTMLArtifact from './HTMLArtifact.vue'
diff --git a/src/renderer/src/components/artifacts/CodeArtifact.vue b/src/renderer/src/components/artifacts/CodeArtifact.vue
index 937d0fcc46..3d22dcc469 100644
--- a/src/renderer/src/components/artifacts/CodeArtifact.vue
+++ b/src/renderer/src/components/artifacts/CodeArtifact.vue
@@ -43,7 +43,7 @@ import { useI18n } from 'vue-i18n'
 import { useThrottleFn } from '@vueuse/core'
 import { Icon } from '@iconify/vue'
 import { MermaidBlockNode } from 'markstream-vue'
-import { DcCopyButton } from '@dc-ui/components/copy-button'
+import { DcCopyButton } from '@dc-ui/components'
 import { useArtifactStore } from '@/stores/artifact'
 import { useUiSettingsStore } from '@/stores/uiSettingsStore'
 import { getLanguageIcon } from 'markstream-vue'
diff --git a/src/renderer/src/components/mcp-config/components/McpJsonViewer.vue b/src/renderer/src/components/mcp-config/components/McpJsonViewer.vue
index 938a31ab49..bae61203b1 100644
--- a/src/renderer/src/components/mcp-config/components/McpJsonViewer.vue
+++ b/src/renderer/src/components/mcp-config/components/McpJsonViewer.vue
@@ -4,7 +4,7 @@ import { DcButton } from '@dc-ui/components/button'
 import { Spinner } from '@shadcn/components/ui/spinner'
 import { Icon } from '@iconify/vue'
 import { useI18n } from 'vue-i18n'
-import { DcCopyButton } from '@dc-ui/components/copy-button'
+import { DcCopyButton } from '@dc-ui/components'
 
 interface Props {
   content: string
diff --git a/src/renderer/src/components/mcp-config/components/McpServers.vue b/src/renderer/src/components/mcp-config/components/McpServers.vue
index 04425b3ded..acb9aad51f 100644
--- a/src/renderer/src/components/mcp-config/components/McpServers.vue
+++ b/src/renderer/src/components/mcp-config/components/McpServers.vue
@@ -15,7 +15,7 @@ import {
   DialogDescription
 } from '@shadcn/components/ui/dialog'
 import { Input } from '@shadcn/components/ui/input'
-import { DcCopyButton } from '@dc-ui/components/copy-button'
+import { DcCopyButton } from '@dc-ui/components'
 import { DcSheetPanel } from '@dc-ui/components/sheet-panel'
 import { DcStatusPill } from '@dc-ui/components/status-pill'
 import { useMcpStore } from '@/stores/mcp'
diff --git a/src/renderer/src/components/message/MessageBlockToolCall.vue b/src/renderer/src/components/message/MessageBlockToolCall.vue
index f4e040b236..f3b648b620 100644
--- a/src/renderer/src/components/message/MessageBlockToolCall.vue
+++ b/src/renderer/src/components/message/MessageBlockToolCall.vue
@@ -248,7 +248,7 @@ import type { DisplayAssistantMessageBlock } from '@/features/chat-page/model/di
 import { parseLiveDelegationSpawnBlock } from '@/lib/liveDelegationToolCall'
 import LiveDelegationToolCallCard from './LiveDelegationToolCallCard.vue'
 import MessageBlockToolCallImagePreview from './MessageBlockToolCallImagePreview.vue'
-import { DcCopyButton } from '@dc-ui/components/copy-button'
+import { DcCopyButton } from '@dc-ui/components'
 
 const McpAppView = defineAsyncComponent(() => import('@/components/mcp/McpAppView.vue'))
 
diff --git a/src/renderer/src/components/message/MessageItemAssistant.vue b/src/renderer/src/components/message/MessageItemAssistant.vue
index abb756075f..199a0cac5e 100644
--- a/src/renderer/src/components/message/MessageItemAssistant.vue
+++ b/src/renderer/src/components/message/MessageItemAssistant.vue
@@ -136,6 +136,7 @@
             :show-trace="showTrace"
             :show-memory="memoryActivity.enabled && !isReadOnly"
             :is-read-only="isReadOnly"
+            :copy-text="copyText"
             @retry="handleAction('retry')"
             @delete="handleAction('delete')"
             @copy="handleAction('copy')"
@@ -415,6 +416,31 @@ const currentContent = computed(() => {
   return filterRenderableAssistantBlocks(blocks ?? [])
 })
 
+const copyText = computed(() =>
+  currentContent.value
+    .filter((block) => {
+      if (
+        (block.type === 'reasoning_content' || block.type === 'artifact-thinking') &&
+        !uiSettingsStore.copyWithCotEnabled
+      ) {
+        return false
+      }
+      return true
+    })
+    .map((block) => {
+      const trimmedContent = (block.content ?? '').trim()
+      if (
+        (block.type === 'reasoning_content' || block.type === 'artifact-thinking') &&
+        uiSettingsStore.copyWithCotEnabled
+      ) {
+        return `<think>\n${trimmedContent}\n</think>`
+      }
+      return trimmedContent
+    })
+    .join('\n')
+    .trim()
+)
+
 const promotedImageSources = computed(() =>
   Array.from(
     new Set(
@@ -642,30 +668,7 @@ const handleAction = (action: HandleActionType) => {
   } else if (action === 'delete') {
     emit('delete', currentMessage.value.id)
   } else if (action === 'copy') {
-    deviceClient.copyText(
-      currentContent.value
-        .filter((block) => {
-          if (
-            (block.type === 'reasoning_content' || block.type === 'artifact-thinking') &&
-            !uiSettingsStore.copyWithCotEnabled
-          ) {
-            return false
-          }
-          return true
-        })
-        .map((block) => {
-          const trimmedContent = (block.content ?? '').trim()
-          if (
-            (block.type === 'reasoning_content' || block.type === 'artifact-thinking') &&
-            uiSettingsStore.copyWithCotEnabled
-          ) {
-            return `<think>\n${trimmedContent}\n</think>`
-          }
-          return trimmedContent
-        })
-        .join('\n')
-        .trim()
-    )
+    deviceClient.copyText(copyText.value)
   } else if (action === 'prev' || action === 'next') {
     if (!useLegacyActions.value) {
       return
diff --git a/src/renderer/src/components/message/MessageItemUser.vue b/src/renderer/src/components/message/MessageItemUser.vue
index a30fac02cf..6dbe8c029e 100644
--- a/src/renderer/src/components/message/MessageItemUser.vue
+++ b/src/renderer/src/components/message/MessageItemUser.vue
@@ -109,6 +109,7 @@
         :is-edit-mode="isEditMode"
         :is-capturing-image="false"
         :is-read-only="effectiveReadOnly"
+        :copy-text="copyText"
         @retry="onRetryAction"
         @delete="handleAction('delete')"
         @copy="handleAction('copy')"
@@ -324,6 +325,8 @@ const getCopyText = () => {
   return props.message.content.text || ''
 }
 
+const copyText = computed(() => getCopyText())
+
 const cancelEdit = () => {
   isEditMode.value = false
 }
diff --git a/src/renderer/src/components/message/MessageToolbar.vue b/src/renderer/src/components/message/MessageToolbar.vue
index a3427d0447..06c703df93 100644
--- a/src/renderer/src/components/message/MessageToolbar.vue
+++ b/src/renderer/src/components/message/MessageToolbar.vue
@@ -12,7 +12,6 @@
               variant="ghost"
               size="icon-sm"
               icon="lucide:check"
-              icon-size="3"
               :tooltip="t('thread.toolbar.save')"
               :tooltip-delay-duration="200"
               class="w-4 h-4 min-w-0 min-h-0 p-0 text-muted-foreground hover:text-primary hover:bg-transparent transition-colors duration-[var(--dc-motion-fast)] ease-[var(--dc-ease-out-soft)]"
@@ -22,7 +21,6 @@
               variant="ghost"
               size="icon-sm"
               icon="lucide:x"
-              icon-size="3"
               :tooltip="t('thread.toolbar.cancel')"
               :tooltip-delay-duration="200"
               class="w-4 h-4 min-w-0 min-h-0 p-0 text-muted-foreground hover:text-primary hover:bg-transparent transition-colors duration-[var(--dc-motion-fast)] ease-[var(--dc-ease-out-soft)]"
@@ -37,7 +35,6 @@
               variant="ghost"
               size="icon-sm"
               icon="lucide:refresh-cw"
-              icon-size="3"
               :tooltip="t('thread.toolbar.retry')"
               :tooltip-delay-duration="200"
               class="text-muted-foreground hover:text-primary hover:bg-transparent transition-colors duration-[var(--dc-motion-fast)] ease-[var(--dc-ease-out-soft)]"
@@ -49,7 +46,6 @@
               variant="ghost"
               size="icon-sm"
               icon="lucide:chevron-left"
-              icon-size="3"
               :tooltip="t('thread.toolbar.previousVariant')"
               :tooltip-delay-duration="200"
               class="text-muted-foreground hover:text-primary hover:bg-transparent transition-colors duration-[var(--dc-motion-fast)] ease-[var(--dc-ease-out-soft)]"
@@ -64,35 +60,25 @@
               variant="ghost"
               size="icon-sm"
               icon="lucide:chevron-right"
-              icon-size="3"
               :tooltip="t('thread.toolbar.nextVariant')"
               :tooltip-delay-duration="200"
               class="text-muted-foreground hover:text-primary hover:bg-transparent transition-colors duration-[var(--dc-motion-fast)] ease-[var(--dc-ease-out-soft)]"
               @click="emit('next')"
             />
-            <DcButton
+            <DcCopyButton
               size="icon-sm"
-              icon="lucide:copy"
-              icon-size="3"
               variant="ghost"
               :tooltip="t('thread.toolbar.copy')"
               :tooltip-ignore-non-keyboard-focus="true"
+              :copy-text="copyText"
               class="relative text-muted-foreground hover:text-primary hover:bg-transparent transition-colors duration-[var(--dc-motion-fast)] ease-[var(--dc-ease-out-soft)]"
-              @click="handleCopy"
-            >
-              <span
-                v-if="showCopyTip"
-                class="absolute -top-6 left-1/2 transform -translate-x-1/2 bg-background border px-2 py-1 rounded text-xs whitespace-nowrap z-[var(--dc-z-popover)]"
-              >
-                {{ t('common.copySuccess') }}
-              </span>
-            </DcButton>
+              @copied="emit('copy')"
+            />
             <DcButton
               v-if="isAssistant"
               variant="ghost"
               size="icon-sm"
               icon="lucide:images"
-              icon-size="3"
               :loading="isCapturingImage"
               :disabled="isCapturingImage"
               :tooltip="
@@ -125,7 +111,6 @@
               variant="ghost"
               size="icon-sm"
               icon="lucide:refresh-cw"
-              icon-size="3"
               :tooltip="t('thread.toolbar.retry')"
               :tooltip-delay-duration="200"
               class="text-muted-foreground hover:text-primary hover:bg-transparent transition-colors duration-[var(--dc-motion-fast)] ease-[var(--dc-ease-out-soft)]"
@@ -136,7 +121,6 @@
               variant="ghost"
               size="icon-sm"
               icon="lucide:bug"
-              icon-size="3"
               :tooltip="t('thread.toolbar.trace')"
               class="text-muted-foreground hover:text-primary hover:bg-transparent transition-colors duration-[var(--dc-motion-fast)] ease-[var(--dc-ease-out-soft)]"
               @click="emit('trace')"
@@ -146,7 +130,6 @@
               variant="ghost"
               size="icon-sm"
               icon="lucide:brain"
-              icon-size="3"
               :tooltip="t('chat.memory.toolbar')"
               class="text-muted-foreground hover:text-primary hover:bg-transparent transition-colors duration-[var(--dc-motion-fast)] ease-[var(--dc-ease-out-soft)]"
               @click="emit('memory')"
@@ -156,7 +139,6 @@
               variant="ghost"
               size="icon-sm"
               icon="lucide:git-branch"
-              icon-size="3"
               :tooltip="t('thread.toolbar.fork')"
               class="text-muted-foreground hover:text-primary hover:bg-transparent transition-colors duration-[var(--dc-motion-fast)] ease-[var(--dc-ease-out-soft)]"
               @click="emit('fork')"
@@ -176,7 +158,6 @@
               variant="ghost"
               size="icon-sm"
               icon="lucide:trash-2"
-              icon-size="3"
               :tooltip="t('thread.toolbar.delete')"
               class="text-destructive/70 hover:text-destructive hover:bg-destructive/10 transition-colors duration-[var(--dc-motion-fast)] ease-[var(--dc-ease-out-soft)]"
               @click="emit('delete')"
@@ -201,7 +182,7 @@
 
 <script setup lang="ts">
 import { Icon } from '@iconify/vue'
-import { DcButton } from '@dc-ui/components/button'
+import { DcCopyButton, DcButton } from '@dc-ui/components'
 import { computed, onBeforeUnmount, ref, type Ref } from 'vue'
 import { TooltipProvider } from '@shadcn/components/ui/tooltip'
 import { useI18n } from 'vue-i18n'
@@ -212,14 +193,12 @@ const uiSettingsStore = useUiSettingsStore()
 
 const traceDebugEnabled = computed(() => uiSettingsStore.traceDebugEnabled)
 
-const showCopyTip = ref(false)
 const showCopyImageTip = ref(false)
 const showCopyFromTopTip = ref(false)
 
 let copyImagePressTimer: number | null = null
-type TipTimerKey = 'copy' | 'copyImage' | 'copyFromTop'
+type TipTimerKey = 'copyImage' | 'copyFromTop'
 const tipTimers: Record<TipTimerKey, number | null> = {
-  copy: null,
   copyImage: null,
   copyFromTop: null
 }
@@ -236,11 +215,6 @@ const flashTip = (tip: Ref<boolean>, timerKey: TipTimerKey) => {
   }, TIP_DURATION)
 }
 
-const handleCopy = () => {
-  emit('copy')
-  flashTip(showCopyTip, 'copy')
-}
-
 const handleCopyImageStart = () => {
   copyImagePressTimer = window.setTimeout(() => {
     // 长按触发：从顶部开始截图
@@ -300,6 +274,7 @@ const props = defineProps<{
   isCapturingImage: boolean
   showTrace?: boolean
   showMemory?: boolean
+  copyText: string
   isReadOnly?: boolean
 }>()
 const emit = defineEmits<{
diff --git a/src/renderer/src/components/trace/TraceDialog.vue b/src/renderer/src/components/trace/TraceDialog.vue
index 980b80fb39..b1f69b73b1 100644
--- a/src/renderer/src/components/trace/TraceDialog.vue
+++ b/src/renderer/src/components/trace/TraceDialog.vue
@@ -318,7 +318,7 @@ import {
 } from '@shadcn/components/ui/select'
 import { Tabs, TabsContent, TabsList, TabsTrigger } from '@shadcn/components/ui/tabs'
 import { DcBadge } from '@dc-ui/components/badge'
-import { DcCopyButton } from '@dc-ui/components/copy-button'
+import { DcCopyButton } from '@dc-ui/components'
 import { Spinner } from '@shadcn/components/ui/spinner'
 import { Icon } from '@iconify/vue'
 import { useI18n } from 'vue-i18n'
diff --git a/src/renderer/src/features/chat-page/composables/useComposerSubmit.ts b/src/renderer/src/features/chat-page/composables/useComposerSubmit.ts
index bb45cb820f..480e47659c 100644
--- a/src/renderer/src/features/chat-page/composables/useComposerSubmit.ts
+++ b/src/renderer/src/features/chat-page/composables/useComposerSubmit.ts
@@ -32,6 +32,11 @@ import {
   type ComposerSessionDraft,
   type ComposerSubmissionSnapshot
 } from '../model/composerDraftState'
+import {
+  DRAFT_PERSISTENCE_DEBOUNCE_MS,
+  loadComposerDraftFromStorage,
+  saveComposerDraftToStorage
+} from '../model/composerDraftPersistence'
 import type { RendererNotificationNotifier } from '@renderer-notifications/rendererNotificationPort'
 
 type MessageStore = ReturnType<typeof useMessageStore>
@@ -486,6 +491,66 @@ export function useComposerSubmit(options: UseComposerSubmitOptions) {
     return copyComposerDocument(document ?? createComposerTextDocument(rawMessage))
   }
 
+  let composerDraftPersistTimer: ReturnType<typeof setTimeout> | null = null
+
+  /**
+   * Read-only snapshot of the live composer for persistence. Unlike `captureLiveDraft` it never
+   * bumps revisions or fingerprints, so a debounced background timer cannot perturb draft tracking.
+   */
+  function captureDraftForPersistence(sessionId: string): ComposerSessionDraft {
+    const deferredDraft =
+      !chatInputRef.value && pendingHandleRestoreSessionId === sessionId
+        ? sessionDrafts.get(sessionId)
+        : undefined
+    return {
+      revision: draftRevisions.get(sessionId) ?? 0,
+      rawMessage: message.value,
+      files: copyComposerFiles(attachedFiles.value),
+      activeSkills: deferredDraft ? [...deferredDraft.activeSkills] : getComposerSkillsSnapshot(),
+      document: deferredDraft
+        ? copyComposerDocument(deferredDraft.document)
+        : getComposerDocumentSnapshot(message.value)
+    }
+  }
+
+  function persistComposerDraft(sessionId: string): void {
+    if (!sessionId) {
+      return
+    }
+    saveComposerDraftToStorage(sessionId, captureDraftForPersistence(sessionId))
+  }
+
+  function scheduleComposerDraftPersist(sessionId: string): void {
+    if (!sessionId) {
+      return
+    }
+    if (composerDraftPersistTimer) {
+      clearTimeout(composerDraftPersistTimer)
+    }
+    composerDraftPersistTimer = setTimeout(() => {
+      composerDraftPersistTimer = null
+      persistComposerDraft(sessionId)
+    }, DRAFT_PERSISTENCE_DEBOUNCE_MS)
+  }
+
+  function flushComposerDraftPersist(): void {
+    if (composerDraftPersistTimer) {
+      clearTimeout(composerDraftPersistTimer)
+      composerDraftPersistTimer = null
+    }
+    if (activeDraftSessionId) {
+      persistComposerDraft(activeDraftSessionId)
+    }
+  }
+
+  // Window teardown (app close / crash-free reload) can bypass the component unmount hook in
+  // Electron, so flush synchronously on pagehide/beforeunload as well.
+  const flushComposerDraftOnPageHide = () => flushComposerDraftPersist()
+  if (typeof window !== 'undefined') {
+    window.addEventListener('pagehide', flushComposerDraftOnPageHide)
+    window.addEventListener('beforeunload', flushComposerDraftOnPageHide)
+  }
+
   function captureLiveDraft(sessionId: string): ComposerSessionDraft {
     let revision = draftRevisions.get(sessionId) ?? 0
     const deferredDraft =
@@ -558,11 +623,13 @@ export function useComposerSubmit(options: UseComposerSubmitOptions) {
       }
       suppressedDraftMutations = Math.max(0, suppressedDraftMutations - 1)
     })
+    scheduleComposerDraftPersist(sessionId)
   }
 
   function markCurrentDraftChanged(): void {
     if (suppressedDraftMutations > 0 || !activeDraftSessionId) return
     nextRevision(activeDraftSessionId)
+    scheduleComposerDraftPersist(activeDraftSessionId)
   }
 
   function recordComposerDocumentChange(): void {
@@ -580,18 +647,34 @@ export function useComposerSubmit(options: UseComposerSubmitOptions) {
   }
 
   function switchComposerSession(previousSessionId: string | undefined, sessionId: string): void {
+    // Flush any pending debounce before the editor starts to show another session's content, so a
+    // late timer can never persist the incoming draft under the outgoing session's storage key.
+    if (composerDraftPersistTimer) {
+      clearTimeout(composerDraftPersistTimer)
+      composerDraftPersistTimer = null
+    }
     const outgoingSessionId = previousSessionId || activeDraftSessionId
-    if (outgoingSessionId && outgoingSessionId === activeDraftSessionId) {
+    // On initial mount previousSessionId is undefined and outgoing === incoming, so there is no
+    // draft to take away — persisting the empty initial draft there would wipe a stored draft
+    // before it can be restored below.
+    if (
+      outgoingSessionId &&
+      outgoingSessionId === activeDraftSessionId &&
+      outgoingSessionId !== sessionId
+    ) {
       const outgoingDraft = applyPendingAcceptedSubmissions(
         outgoingSessionId,
         captureLiveDraft(outgoingSessionId)
       )
       sessionDrafts.set(outgoingSessionId, outgoingDraft)
       observedDraftFingerprints.set(outgoingSessionId, composerDraftFingerprint(outgoingDraft))
+      saveComposerDraftToStorage(outgoingSessionId, outgoingDraft)
     }
 
     const storedIncomingDraft =
-      sessionDrafts.get(sessionId) ?? createEmptyComposerDraft(draftRevisions.get(sessionId) ?? 0)
+      sessionDrafts.get(sessionId) ??
+      loadComposerDraftFromStorage(sessionId) ??
+      createEmptyComposerDraft(draftRevisions.get(sessionId) ?? 0)
     const incomingDraft = applyPendingAcceptedSubmissions(sessionId, storedIncomingDraft)
     applyLiveDraft(sessionId, incomingDraft)
   }
@@ -642,6 +725,7 @@ export function useComposerSubmit(options: UseComposerSubmitOptions) {
       sessionDrafts.set(sessionId, copyComposerDraft(nextDraft))
       observedDraftFingerprints.set(sessionId, composerDraftFingerprint(nextDraft))
       draftRevisions.set(sessionId, nextDraft.revision)
+      saveComposerDraftToStorage(sessionId, nextDraft)
     }
   }
 
@@ -1090,6 +1174,7 @@ export function useComposerSubmit(options: UseComposerSubmitOptions) {
     }
     sessionDrafts.set(sessionId, nextDraft)
     observedDraftFingerprints.set(sessionId, composerDraftFingerprint(nextDraft))
+    saveComposerDraftToStorage(sessionId, nextDraft)
   }
 
   function restoreInitialBlockedDraft(
@@ -1179,6 +1264,11 @@ export function useComposerSubmit(options: UseComposerSubmitOptions) {
   }
 
   function dispose(): void {
+    flushComposerDraftPersist()
+    if (typeof window !== 'undefined') {
+      window.removeEventListener('pagehide', flushComposerDraftOnPageHide)
+      window.removeEventListener('beforeunload', flushComposerDraftOnPageHide)
+    }
     searchCapabilityRequestId += 1
     stopSearchCapabilityWatch()
     removeProvidersChangedListener()
diff --git a/src/renderer/src/features/chat-page/model/composerDraftPersistence.ts b/src/renderer/src/features/chat-page/model/composerDraftPersistence.ts
new file mode 100644
index 0000000000..ad85598154
--- /dev/null
+++ b/src/renderer/src/features/chat-page/model/composerDraftPersistence.ts
@@ -0,0 +1,160 @@
+import type { JSONContent } from '@tiptap/core'
+import type { MessageFile } from '@shared/types/agent-interface'
+import type { ComposerSessionDraft } from './composerDraftState'
+import { isComposerDraftEmpty } from './composerDraftState'
+
+/**
+ * Per-session composer draft persistence. The draft (typed text, attachments, active skills and the
+ * TipTap document) is kept in memory while the app runs so switching sessions restores it instantly,
+ * and mirrored to localStorage so an app restart does not lose it. Empty drafts are never written and
+ * remove any previously stored value.
+ */
+const COMPOSER_DRAFT_STORAGE_PREFIX = 'deepchat.composerDraft.v1.'
+const DRAFT_PERSISTENCE_DEBOUNCE_MS = 400
+
+function storageKey(sessionId: string): string {
+  return `${COMPOSER_DRAFT_STORAGE_PREFIX}${sessionId}`
+}
+
+function getStorage(): Storage | null {
+  if (typeof window === 'undefined') {
+    return null
+  }
+  try {
+    return window.localStorage ?? null
+  } catch {
+    return null
+  }
+}
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === 'object' && value !== null && !Array.isArray(value)
+}
+
+function isStringArray(value: unknown): value is string[] {
+  return Array.isArray(value) && value.every((item) => typeof item === 'string' && item.length > 0)
+}
+
+function isJsonContent(value: unknown): value is JSONContent {
+  if (!isRecord(value) || typeof value.type !== 'string') {
+    return false
+  }
+  if (value.content !== undefined) {
+    if (!Array.isArray(value.content) || !value.content.every(isJsonContent)) {
+      return false
+    }
+  }
+  if (value.text !== undefined && typeof value.text !== 'string') {
+    return false
+  }
+  return value.attrs === undefined || isRecord(value.attrs)
+}
+
+function hasValidPdfTextCoverage(value: Record<string, unknown>): boolean {
+  if (value.pdfTextCoverage === undefined) {
+    return true
+  }
+  const coverage = value.pdfTextCoverage
+  return (
+    isRecord(coverage) &&
+    typeof coverage.routingRevision === 'string' &&
+    typeof coverage.pageCount === 'number' &&
+    typeof coverage.substantivePageCount === 'number' &&
+    typeof coverage.lowTextPageCount === 'number' &&
+    Array.isArray(coverage.lowTextPageSamples) &&
+    coverage.lowTextPageSamples.every((item) => typeof item === 'number') &&
+    typeof coverage.hasEmbeddedText === 'boolean'
+  )
+}
+
+function isMessageFile(value: unknown): value is MessageFile {
+  if (!isRecord(value) || typeof value.name !== 'string' || typeof value.path !== 'string') {
+    return false
+  }
+  return (
+    (value.type === undefined || typeof value.type === 'string') &&
+    (value.size === undefined || typeof value.size === 'number') &&
+    (value.content === undefined || typeof value.content === 'string') &&
+    (value.mimeType === undefined || typeof value.mimeType === 'string') &&
+    (value.token === undefined || typeof value.token === 'number') &&
+    (value.thumbnail === undefined || typeof value.thumbnail === 'string') &&
+    (value.requestedRepresentation === undefined ||
+      typeof value.requestedRepresentation === 'string') &&
+    (value.resolvedRepresentation === undefined || isRecord(value.resolvedRepresentation)) &&
+    (value.metadata === undefined || isRecord(value.metadata)) &&
+    hasValidPdfTextCoverage(value)
+  )
+}
+
+function parseComposerDraft(value: unknown): ComposerSessionDraft | null {
+  if (
+    !isRecord(value) ||
+    typeof value.rawMessage !== 'string' ||
+    typeof value.revision !== 'number' ||
+    !Array.isArray(value.files) ||
+    !value.files.every(isMessageFile) ||
+    !isStringArray(value.activeSkills) ||
+    !isJsonContent(value.document)
+  ) {
+    return null
+  }
+
+  return {
+    revision: value.revision,
+    rawMessage: value.rawMessage,
+    files: value.files,
+    activeSkills: value.activeSkills,
+    document: value.document
+  }
+}
+
+export function loadComposerDraftFromStorage(sessionId: string): ComposerSessionDraft | null {
+  const storage = getStorage()
+  if (!storage || !sessionId) {
+    return null
+  }
+  try {
+    const raw = storage.getItem(storageKey(sessionId))
+    if (!raw) {
+      return null
+    }
+    const draft = parseComposerDraft(JSON.parse(raw))
+    if (!draft || isComposerDraftEmpty(draft)) {
+      return null
+    }
+    return draft
+  } catch {
+    // Corrupted or unreadable draft payloads are treated as absent; the user just gets a clean box.
+    return null
+  }
+}
+
+export function saveComposerDraftToStorage(sessionId: string, draft: ComposerSessionDraft): void {
+  const storage = getStorage()
+  if (!storage || !sessionId) {
+    return
+  }
+  try {
+    if (isComposerDraftEmpty(draft)) {
+      storage.removeItem(storageKey(sessionId))
+      return
+    }
+    storage.setItem(storageKey(sessionId), JSON.stringify(draft))
+  } catch {
+    // Storage can be unavailable (private mode, quota). Draft persistence is best-effort.
+  }
+}
+
+export function clearComposerDraftFromStorage(sessionId: string): void {
+  const storage = getStorage()
+  if (!storage || !sessionId) {
+    return
+  }
+  try {
+    storage.removeItem(storageKey(sessionId))
+  } catch {
+    // Ignore storage failures; the in-memory draft still works for this run.
+  }
+}
+
+export { DRAFT_PERSISTENCE_DEBOUNCE_MS }
diff --git a/test/renderer/components/ChatPage.test.ts b/test/renderer/components/ChatPage.test.ts
index 0717c88547..fbc9a9fbb8 100644
--- a/test/renderer/components/ChatPage.test.ts
+++ b/test/renderer/components/ChatPage.test.ts
@@ -1,4 +1,4 @@
-import { describe, expect, it, vi } from 'vitest'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
 import { defineComponent, h, provide, reactive, ref } from 'vue'
 import { flushPromises, mount } from '@vue/test-utils'
 import { WORKSPACE_EVENTS } from '@/events'
@@ -448,6 +448,10 @@ const setup = async (options: SetupOptions = {}) => {
     default: defineComponent({
       name: 'ChatInputBox',
       props: {
+        modelValue: {
+          type: String,
+          default: ''
+        },
         files: {
           type: Array,
           default: () => []
@@ -498,7 +502,7 @@ const setup = async (options: SetupOptions = {}) => {
         })
       },
       template:
-        '<div class="chat-input-box-stub" :data-agent-id="agentId"><slot name="toolbar" /></div>'
+        '<div class="chat-input-box-stub" :data-agent-id="agentId" :data-model-value="modelValue"><slot name="toolbar" /></div>'
     })
   }))
   vi.doMock('@/components/chat/ChatInputToolbar.vue', () => ({
@@ -775,6 +779,10 @@ async function expectSessionRestoreTransactionStopsAfter(
 }
 
 describe('ChatPage', () => {
+  beforeEach(() => {
+    localStorage.clear()
+  })
+
   it('passes the active session Agent to the ChatInputBox Skill scope', async () => {
     const { wrapper } = await setup({
       activeSessionPatch: { agentId: 'agent-b' }
@@ -3689,4 +3697,18 @@ describe('ChatPage', () => {
     expect(spotlightStore.clearPendingMessageJump).toHaveBeenCalled()
     vi.useRealTimers()
   })
+
+  it('persists the composer draft through a ChatPage unmount', async () => {
+    // ChatTabView keys ChatPage by sessionId, so switching conversations unmounts the page. The
+    // unmount flush must write the draft to storage so the next keyed mount of the same session
+    // (covered by the useComposerSubmit remount test) can restore it.
+    const first = await setup()
+    const firstInput = first.wrapper.findComponent({ name: 'ChatInputBox' })
+    firstInput.vm.$emit('update:modelValue', 'draft from previous page')
+    await flushPromises()
+    first.wrapper.unmount()
+
+    const stored = JSON.parse(localStorage.getItem('deepchat.composerDraft.v1.s1') ?? 'null')
+    expect(stored?.rawMessage).toBe('draft from previous page')
+  })
 })
diff --git a/test/renderer/components/DcCopyButton.test.ts b/test/renderer/components/DcCopyButton.test.ts
new file mode 100644
index 0000000000..52aa9de845
--- /dev/null
+++ b/test/renderer/components/DcCopyButton.test.ts
@@ -0,0 +1,98 @@
+import { defineComponent, nextTick } from 'vue'
+import { mount } from '@vue/test-utils'
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
+import DcCopyButton from '@dc-ui/components/button/DcCopyButton.vue'
+
+const { copyMock } = vi.hoisted(() => ({
+  copyMock: vi.fn()
+}))
+
+vi.mock('@vueuse/core', () => ({
+  useClipboard: () => ({
+    copy: copyMock
+  })
+}))
+
+vi.mock('@iconify/vue', () => ({
+  Icon: {
+    name: 'Icon',
+    props: ['icon'],
+    template: '<span :data-icon="icon"></span>'
+  }
+}))
+
+describe('DcCopyButton', () => {
+  beforeEach(() => {
+    vi.useFakeTimers()
+    copyMock.mockReset()
+    copyMock.mockResolvedValue(undefined)
+  })
+
+  afterEach(() => {
+    vi.useRealTimers()
+  })
+
+  it('copies copyText, emits copied, and resets the success state', async () => {
+    const wrapper = mount(DcCopyButton, {
+      props: {
+        copyText: 'hello'
+      },
+      attrs: {
+        label: 'Copy'
+      }
+    })
+
+    await wrapper.get('button').trigger('click')
+
+    await vi.waitFor(() => expect(copyMock).toHaveBeenCalledWith('hello'))
+    await vi.waitFor(() => expect(wrapper.emitted('copied')).toHaveLength(1))
+    expect(wrapper.find('[data-icon="lucide:check"]').exists()).toBe(true)
+    expect(wrapper.get('button').classes()).toContain('text-emerald-600')
+
+    await vi.advanceTimersByTimeAsync(1200)
+    await nextTick()
+
+    expect(wrapper.find('[data-icon="lucide:copy"]').exists()).toBe(true)
+  })
+
+  it('emits error when clipboard copying fails', async () => {
+    const error = new Error('copy failed')
+    const errorSpy = vi.spyOn(console, 'error').mockImplementation(() => undefined)
+    copyMock.mockRejectedValueOnce(error)
+    const wrapper = mount(DcCopyButton, {
+      props: {
+        copyText: 'hello'
+      },
+      attrs: {
+        label: 'Copy'
+      }
+    })
+
+    await wrapper.get('button').trigger('click')
+
+    await vi.waitFor(() => expect(wrapper.emitted('error')?.[0]).toEqual([error]))
+    expect(wrapper.emitted('copied')).toBeUndefined()
+    expect(wrapper.find('[data-icon="lucide:copy"]').exists()).toBe(true)
+    errorSpy.mockRestore()
+  })
+
+  it('preserves inherited click handlers and modifiers', async () => {
+    const parentClick = vi.fn()
+    const childClick = vi.fn()
+    const Wrapper = defineComponent({
+      components: { DcCopyButton },
+      setup() {
+        return { parentClick, childClick }
+      },
+      template:
+        '<div @click="parentClick"><DcCopyButton copy-text="hello" label="Copy" @click.stop="childClick" /></div>'
+    })
+    const wrapper = mount(Wrapper)
+
+    await wrapper.get('button').trigger('click')
+
+    await vi.waitFor(() => expect(copyMock).toHaveBeenCalledWith('hello'))
+    expect(childClick).toHaveBeenCalledTimes(1)
+    expect(parentClick).not.toHaveBeenCalled()
+  })
+})
diff --git a/test/renderer/components/message/MessageToolbar.trace.test.ts b/test/renderer/components/message/MessageToolbar.trace.test.ts
index 0f70ca81e1..2ee958cb92 100644
--- a/test/renderer/components/message/MessageToolbar.trace.test.ts
+++ b/test/renderer/components/message/MessageToolbar.trace.test.ts
@@ -26,7 +26,7 @@ vi.mock('vue-i18n', () => ({
 }))
 
 vi.mock(
-  '@dc-ui/components/button',
+  '@dc-ui/components',
   () => ({
     DcButton: {
       name: 'Button',
@@ -34,6 +34,14 @@ vi.mock(
       props: ['icon'],
       template:
         '<button v-bind="$attrs" @click="$emit(\'click\')"><span v-if="icon" :data-icon="icon"></span><slot /></button>'
+    },
+    DcCopyButton: {
+      name: 'CopyButton',
+      inheritAttrs: false,
+      props: ['icon', 'copyText'],
+      emits: ['copied'],
+      template:
+        '<button v-bind="$attrs" @click="$emit(\'copied\')"><span :data-icon="icon || \'lucide:copy\'"></span><slot /></button>'
     }
   }),
   { virtual: true }
@@ -79,7 +87,8 @@ const baseProps = {
   isCapturingImage: false,
   showTrace: true,
   isInGeneratingThread: false,
-  isReadOnly: false
+  isReadOnly: false,
+  copyText: 'copy me'
 }
 
 const mountToolbar = () =>
@@ -114,6 +123,14 @@ describe('MessageToolbar trace button visibility', () => {
     expect(wrapper.emitted().copyImageFromTop).toHaveLength(2)
   })
 
+  it('preserves the copy event contract', async () => {
+    const wrapper = mountToolbar()
+
+    await wrapper.find('[data-icon="lucide:copy"]').trigger('click')
+
+    expect(wrapper.emitted().copy).toHaveLength(1)
+  })
+
   it('shows trace button only when trace debug is enabled and message allows trace', async () => {
     traceDebugEnabled = true
     const wrapper = mountToolbar()
diff --git a/test/renderer/features/chat-page/composables/useComposerSubmit.test.ts b/test/renderer/features/chat-page/composables/useComposerSubmit.test.ts
index 808c0561c7..e90eb57481 100644
--- a/test/renderer/features/chat-page/composables/useComposerSubmit.test.ts
+++ b/test/renderer/features/chat-page/composables/useComposerSubmit.test.ts
@@ -2,6 +2,7 @@ import { computed, effectScope, nextTick, ref, shallowReactive } from 'vue'
 import type { JSONContent } from '@tiptap/core'
 import { beforeEach, describe, expect, it, vi } from 'vitest'
 import { useComposerSubmit } from '@/features/chat-page/composables/useComposerSubmit'
+import { saveComposerDraftToStorage } from '@/features/chat-page/model/composerDraftPersistence'
 import type {
   AttachmentPreparationSummary,
   ChatMessageRecord,
@@ -191,7 +192,10 @@ function createHarness(options: { composerMounted?: boolean } = {}) {
     schedulePostSubmitScrollToBottom,
     openModelPicker,
     notify,
-    stop: () => scope.stop()
+    stop: () => {
+      actions.dispose()
+      scope.stop()
+    }
   }
 }
 
@@ -218,6 +222,7 @@ const blockedSummary = (): AttachmentPreparationSummary => ({
 describe('useComposerSubmit attachment preflight', () => {
   beforeEach(() => {
     vi.clearAllMocks()
+    localStorage.clear()
   })
 
   it('preserves a rejected draft and sends only after explicit degradation', async () => {
@@ -1013,4 +1018,93 @@ describe('useComposerSubmit attachment preflight', () => {
     await vi.waitFor(() => expect(harness.actions.isSearchAvailable.value).toBe(false))
     harness.stop()
   })
+
+  it('persists the typed draft to storage after the debounce', async () => {
+    vi.useFakeTimers()
+    const harness = createHarness()
+    try {
+      harness.actions.message.value = 'persist me'
+      await vi.advanceTimersByTimeAsync(400)
+
+      const stored = JSON.parse(localStorage.getItem('deepchat.composerDraft.v1.s1') ?? 'null')
+      expect(stored?.rawMessage).toBe('persist me')
+    } finally {
+      harness.stop()
+      vi.useRealTimers()
+    }
+  })
+
+  it('restores a persisted draft when switching to its session', () => {
+    const harness = createHarness()
+    saveComposerDraftToStorage('s2', {
+      revision: 2,
+      rawMessage: 'draft from previous run',
+      files: [],
+      activeSkills: [],
+      document: {
+        type: 'doc',
+        content: [
+          { type: 'paragraph', content: [{ type: 'text', text: 'draft from previous run' }] }
+        ]
+      }
+    })
+
+    harness.actions.switchComposerSession('s1', 's2')
+
+    expect(harness.actions.message.value).toBe('draft from previous run')
+    harness.stop()
+  })
+
+  it('persists the outgoing draft when switching away from a session', () => {
+    const harness = createHarness()
+    harness.actions.message.value = 'switch away'
+    harness.actions.attachedFiles.value = []
+
+    harness.actions.switchComposerSession('s1', 's2')
+
+    const stored = JSON.parse(localStorage.getItem('deepchat.composerDraft.v1.s1') ?? 'null')
+    expect(stored?.rawMessage).toBe('switch away')
+    harness.stop()
+  })
+
+  it('restores a draft flushed on unmount when the same session is mounted again', () => {
+    // ChatPage is keyed by sessionId, so switching conversations unmounts the old page. The
+    // dispose() flush must persist the draft so a later mount of the same session restores it.
+    const first = createHarness()
+    first.actions.message.value = 'draft before unmount'
+    first.stop()
+
+    const second = createHarness()
+    second.actions.switchComposerSession(undefined, 's1')
+
+    expect(second.actions.message.value).toBe('draft before unmount')
+    second.stop()
+  })
+
+  it('removes the stored draft after an accepted submission clears the composer', async () => {
+    vi.useFakeTimers()
+    const harness = createHarness()
+    try {
+      saveComposerDraftToStorage('s1', {
+        revision: 1,
+        rawMessage: 'to be sent',
+        files: [],
+        activeSkills: [],
+        document: {
+          type: 'doc',
+          content: [{ type: 'paragraph', content: [{ type: 'text', text: 'to be sent' }] }]
+        }
+      })
+      harness.actions.message.value = 'to be sent'
+
+      await harness.actions.onSubmit()
+
+      expect(harness.actions.message.value).toBe('')
+      await vi.advanceTimersByTimeAsync(400)
+      expect(localStorage.getItem('deepchat.composerDraft.v1.s1')).toBeNull()
+    } finally {
+      harness.stop()
+      vi.useRealTimers()
+    }
+  })
 })
diff --git a/test/renderer/features/chat-page/model/composerDraftPersistence.test.ts b/test/renderer/features/chat-page/model/composerDraftPersistence.test.ts
new file mode 100644
index 0000000000..b002fa7fcd
--- /dev/null
+++ b/test/renderer/features/chat-page/model/composerDraftPersistence.test.ts
@@ -0,0 +1,109 @@
+import { describe, expect, it, vi } from 'vitest'
+import {
+  clearComposerDraftFromStorage,
+  loadComposerDraftFromStorage,
+  saveComposerDraftToStorage
+} from '@/features/chat-page/model/composerDraftPersistence'
+import { createEmptyComposerDraft } from '@/features/chat-page/model/composerDraftState'
+
+function createDraft(rawMessage = 'hello') {
+  return {
+    revision: 3,
+    rawMessage,
+    files: [],
+    activeSkills: [],
+    document: {
+      type: 'doc',
+      content: [{ type: 'paragraph', content: [{ type: 'text', text: rawMessage }] }]
+    }
+  }
+}
+
+describe('composerDraftPersistence', () => {
+  beforeEach(() => {
+    localStorage.clear()
+  })
+
+  it('round-trips a draft through localStorage', () => {
+    const draft = createDraft('draft text')
+
+    saveComposerDraftToStorage('s1', draft)
+
+    expect(loadComposerDraftFromStorage('s1')).toEqual(draft)
+  })
+
+  it('does not store empty drafts and clears an existing key', () => {
+    saveComposerDraftToStorage('s1', createDraft('filled'))
+    saveComposerDraftToStorage('s1', createEmptyComposerDraft())
+
+    expect(loadComposerDraftFromStorage('s1')).toBeNull()
+    expect(loadComposerDraftFromStorage('s1')).toBeNull()
+  })
+
+  it('treats corrupted or malformed payloads as absent', () => {
+    localStorage.setItem('deepchat.composerDraft.v1.s1', 'not-json{')
+    expect(loadComposerDraftFromStorage('s1')).toBeNull()
+
+    localStorage.setItem(
+      'deepchat.composerDraft.v1.s2',
+      JSON.stringify({ rawMessage: 'missing fields' })
+    )
+    expect(loadComposerDraftFromStorage('s2')).toBeNull()
+  })
+
+  it('rejects malformed nested draft fields', () => {
+    const invalidPayloads = [
+      { ...createDraft(), files: [null] },
+      { ...createDraft(), files: [{ name: 'missing path' }] },
+      { ...createDraft(), files: [{ name: 'a', path: 'a', pdfTextCoverage: {} }] },
+      { ...createDraft(), activeSkills: ['valid', 123] },
+      { ...createDraft(), activeSkills: [''] },
+      { ...createDraft(), document: { type: 'doc', content: [null] } },
+      { ...createDraft(), document: { type: 'doc', attrs: [] } }
+    ]
+
+    invalidPayloads.forEach((payload, index) => {
+      localStorage.setItem(`deepchat.composerDraft.v1.invalid-${index}`, JSON.stringify(payload))
+      expect(loadComposerDraftFromStorage(`invalid-${index}`)).toBeNull()
+    })
+  })
+
+  it('returns null when no window storage is available', () => {
+    const { window } = globalThis
+    vi.stubGlobal('window', undefined)
+    try {
+      expect(loadComposerDraftFromStorage('s1')).toBeNull()
+      expect(() => saveComposerDraftToStorage('s1', createDraft())).not.toThrow()
+      expect(() => clearComposerDraftFromStorage('s1')).not.toThrow()
+    } finally {
+      vi.unstubAllGlobals()
+      if (window) globalThis.window = window
+    }
+  })
+
+  it('ignores localStorage getter failures', () => {
+    const { window } = globalThis
+    vi.stubGlobal(
+      'window',
+      Object.defineProperty({}, 'localStorage', {
+        get() {
+          throw new Error('storage blocked')
+        }
+      })
+    )
+    try {
+      expect(loadComposerDraftFromStorage('s1')).toBeNull()
+      expect(() => saveComposerDraftToStorage('s1', createDraft())).not.toThrow()
+      expect(() => clearComposerDraftFromStorage('s1')).not.toThrow()
+    } finally {
+      vi.unstubAllGlobals()
+      if (window) globalThis.window = window
+    }
+  })
+
+  it('explicitly clears a stored draft', () => {
+    saveComposerDraftToStorage('s1', createDraft())
+    clearComposerDraftFromStorage('s1')
+    expect(loadComposerDraftFromStorage('s1')).toBeNull()
+  })
+})