fix(changes): 会话事件改走宿主 changes.ops 路由 + diff 展开二级设置 + 视觉迭代

CI 修复（plugin-mount 的 ctx.sessions.get TypeError ×1003）： - 客户端 runtime 无事件日志面——badge/SessionLens 原在客户端直读 ctx.sessions.get(id).events / ctx.on('session/event')，全部不可达。 - 新增宿主路由 changes.ops：live 会话日志优先，冷会话回放 sessionPersistence.inspect；afterSeq 增量（缺省游标含 seq 0，显式游标为 seq > afterSeq，同 sidechat.events 约定），窗口上限 4000 与客户端累加器一致。 - ChangesTab 轮询（mount 一拉 + visible 2.5s 增量）折入 ops，写模块级 opCounts 缓存供 badge 同步读取；SessionLens 改纯展示。 diff 展开二级设置（changesDiffFloat，默认浮窗）： - prefs 四处接线 + git tab settings select（浮窗/面板，图标选项卡） - 预览面板「展开为 diff tab」按设置落点：浮窗居中弹出或源 pane 下方 split；i18n 全 21 词典同步。视觉迭代（真机挂载截图审查后调整）： - Session 视角：kind 徽章为左轨，大小+相对时间右对齐元列；失败操作行红色内嵌条；文件组头降为三级标签并加组间距。 - Git 视角：untracked '?' 徽章与新增同绿色；stage 按钮改 plus 图标。 - diff 折叠行：可展开折叠带 › 箭头 + 次级对比度，静态 gap 不再显示 pointer/hover；预览头路径改尾部截断（RTL 技巧，保文件名）。验证：typecheck ✓ / vitest 1123 ✓ / pnpm test:mount（钉 alpha.2 CLI） 14/14 ✓；真机挂载截图（badge=5、双视角、浮窗展开）0 console error。
2026-08-31 17:52:59 +08:00
parent 24a3813c63
commit f024fbf092
40 changed files with 456 additions and 112 deletions
@@ -44,7 +44,7 @@
 - **🌐 内嵌浏览器**：多开网页 tab，后退 / 前进 / 刷新；内容运行在沙箱 iframe；外链默认按协议分流——HTTP 在侧边栏打开、HTTPS 走系统浏览器（设置页可分别调整）
 - **💻 真实终端**：xterm.js + node-pty 真实 shell，断线重连回放；可选为模型注入 `terminal_*` 工具
 - **📂 模型侧边栏打开（可选）**：全局设置开启后注入 `sidebar_open` 工具——模型可主动在侧边栏打开文件 / 文件夹（树以该目录为根）/ HTTP(S) 网页
- **🌿 文件变动**：Git 视角（真 diff / 历史 / 暂存·提交·还原 / worktree·子仓库选择）与本轮文件视角（模型读 / 写 / 编辑实时追踪，按文件分组、按类型筛选）**双视角合一**；统一 diff 渲染（改蓝配对 + 行内字符级高亮 + 语法着色 + 上下文折叠），底部可拖拽预览面板，可一键展开为独立 diff tab
+- **🌿 文件变动**：Git 视角（真 diff / 历史 / 暂存·提交·还原 / worktree·子仓库选择）与本轮文件视角（模型读 / 写 / 编辑实时追踪，按文件分组、按类型筛选）**双视角合一**；统一 diff 渲染（改蓝配对 + 行内字符级高亮 + 语法着色 + 上下文折叠），底部可拖拽预览面板，可一键展开为独立 diff tab（默认自由浮窗，可在设置改为面板下半 split）
 - **🧩 后台任务页**：subagent 拓扑 + 后台任务（退出码 / 实时输出 / 强制终止）
 - **💬 侧边对话(beta)**：Codex 风格的侧边线程——继承主会话完整上下文（含进行中的回合与工具调用）独立运行，不进入主会话；线程内可持续追问，一键「保存为新会话」提升为顶层会话
 - **🪟 双工作台**：右侧栏 + 底部面板；拖 Tab 拆分 / 合并分栏（可跨面板），移动端自动合并全宽抽屉
@@ -359,7 +359,7 @@ ctx.effect(() => {
 | id | order | single | hidden | 用途 |
 |---|---|---|---|---|
 | `editor` | 10 | 否（按 path 去重） | 否 | 唯一「文件窗口」（编辑/预览 + 资源管理）。chrome 恒合并形态：路径输入框 + 编辑器控件 + 可开关内嵌文件树（全局搜索 `fs.search`；状态存 `tab.meta.treeOpen/treeWidth`）。`editorExplorer`：关（默认）= 按 path 新开，无路径窗口 = 纯资源管理器；开 = 树点击/Enter 经 `updateTab` 原地切换（id/meta 不变），无路径窗口 = 带 chrome 空窗口。树右键「在新 Tab 中打开」「在侧边打开」（pane 右侧 split）。新会话 seed 空文件窗口（`title:'Files'`）；旧 `explorer` tab 经 `sanitizeState` 迁移 |
-| `git` | 20 | 是 | 否 | 「文件变动」统一 tab（id 保留 `git` 以兼容持久化布局）：**Git 视角**（原 Git 面板：staged/unstaged / 提交 / 历史 / worktree·子仓库选择）+ **本轮文件视角**（原 file-trace：会话事件日志实时折叠的模型读写编辑记录，按文件分组、类型筛选、badge 计数）；两视角共用底部可拖拽预览面板（`tab.meta.lens/previewH` 持久化），diff 渲染统一走 `src/client/diff/`（`DiffRows`/`DiffFiles`：mod 配对 + 行内高亮 + 语法着色 + 上下文折叠） |
+| `git` | 20 | 是 | 是（本轮文件操作数） | 「文件变动」统一 tab（id 保留 `git` 以兼容持久化布局）：**Git 视角**（原 Git 面板：staged/unstaged / 提交 / 历史 / worktree·子仓库选择）+ **本轮文件视角**（原 file-trace：模型读/写/编辑实时折叠，按文件分组、类型筛选）；会话事件经插件自有宿主路由 `changes.ops` 供给（live 日志优先、冷会话回放持久化记录，`afterSeq` 增量），badge 读 tab 轮询写入的同步缓存。两视角共用底部可拖拽预览面板（`tab.meta.lens/previewH` 持久化），diff 渲染统一走 `src/client/diff/`（`DiffRows`/`DiffFiles`：mod 配对 + 行内高亮 + 语法着色 + 上下文折叠）；Git 目标可展开为独立 diff tab——落点由二级设置 `changesDiffFloat` 决定（默认**自由浮窗**居中弹出，可选面板下半 split），设置项见 tab descriptor 的 `settings.toggles` select |
 | `subagent` | 30 | 是 | 否 | 子代理拓扑 |
 | `sidechat` | 35 | 否（`sidechat:<uuid>`，按 `meta.threadId` 去重） | 否 | 侧边对话（每对话一 Tab）：打开即建空线程（首条消息赢得标签并同步标题）；线程 = 插件自建子会话（种子继承父会话上下文，进行中回合以 `interrupted` 闭合；种子带合法 `subagent/descriptor`，SubagentView 按 `Side: ` 前缀过滤），`origin:'subagent'` 隐藏于主列表；走 `/sidebar/api/sidechat.*` 路由；头部菜单切换/重开（`parkSidechatReopen` + 确定性 id），关 Tab 释放 live agent；重开经 `collectOwnEvents` 回源到种子边界；「保存为新会话」= `session.fork`（`this` 敏感）。[设计文档](plans/2026-08-20-sidechat-tab-design.md) |
 | `terminal` | 40 | 否（`terminal:<n>`） | 否 | 终端。v0.17.0+ 右键「固定到工作区/全局」：跨会话不消失，TabBar 内联虚拟 Tab（`pinned:<homeSessionId>:<tabId>`），就地按 home scope 连 PTY；global 全会话可见、workspace 仅同 cwd；`tab.pin = { scope, homeCwd? }` 随会话持久化，渲染期解析（`collectPinnedTabs` → `createPinnedVirtualTab` → `injectPinnedIntoTree`） |
@@ -691,7 +691,7 @@ ctx.effect(() =>
 )
 ```

-> ⚠️ **`toggles` 的 key 必须是宿主 PrefsSchema 的字段**（内置键：`autoOpenSubagent` / `agentTerminalTools` / `agentOpenTools` / `terminalFontFamily` / `terminalFontSize` / `editorExplorer` / `workspaceFence` / `htmlViewerNoSandbox` / `htmlViewerDefaultUnsafe` / `browserNoSandbox` / `browserInterceptLinks` / `browserInterceptHttp` / `browserInterceptHttps`）。**v0.12.0 起设置 seam 已开放**：你自己的设置走 `pluginToggles`（声明式行）或 `render`（自定义面板），值持久化在 `pluginSettings[id]`——不再需要宿主 schema 字段，也不再被 seam 丢弃。值须 JSON 可序列化（行控件只产出 string/number/boolean；自定义面板自行负责）。
+> ⚠️ **`toggles` 的 key 必须是宿主 PrefsSchema 的字段**（内置键：`autoOpenSubagent` / `agentTerminalTools` / `agentOpenTools` / `terminalFontFamily` / `terminalFontSize` / `editorExplorer` / `workspaceFence` / `htmlViewerNoSandbox` / `htmlViewerDefaultUnsafe` / `browserNoSandbox` / `browserInterceptLinks` / `browserInterceptHttp` / `browserInterceptHttps` / `changesDiffFloat`）。**v0.12.0 起设置 seam 已开放**：你自己的设置走 `pluginToggles`（声明式行）或 `render`（自定义面板），值持久化在 `pluginSettings[id]`——不再需要宿主 schema 字段，也不再被 seam 丢弃。值须 JSON 可序列化（行控件只产出 string/number/boolean；自定义面板自行负责）。

 ### 8.1 内置键 `workspaceFence`（工作区路径围栏）

@@ -9,6 +9,7 @@
 import { encodeHtmlUrl } from '../html-route.ts'
 import type { LastActivity } from '../subagent-activity.ts'
 import type { SidechatLogEvent, SidechatThreadInfo } from '../sidechat-core.ts'
+import type { SidebarSessionEvent } from '../context-types.ts'
 import type { BrowserProbeResult } from './browser.ts'

 /** One wire failure. */
@@ -258,6 +259,14 @@ export const api = {
  /** Full patch text of one commit (diff display for the history rows). */
  gitCommitDiff: (scope: SessionScope, hash: string, worktree?: string, signal?: AbortSignal) =>
    call<{ diff: string }>('git.commit-diff', gitPayload(scope, worktree, { hash }), signal),
+  /** The session's file-tool events for the changes tab's session lens: the
+   *  `tool/call` + `tool/result` rows past `afterSeq` (0 = whole window),
+   *  capped to the recent window host-side. The client runtime exposes no
+   *  event-log face, so the lens polls this delta route. */
+  changesOps: (scope: SessionScope, afterSeq?: number, signal?: AbortSignal) =>
+    call<{ events: SidebarSessionEvent[]; lastSeq: number }>('changes.ops', scopePayload(scope, {
+      ...(afterSeq !== undefined && afterSeq > 0 ? { afterSeq } : {}),
+    }), signal),
  /** Discard the worktree changes of one file (the index is untouched). */
  gitDiscard: (scope: SessionScope, path: string, worktree?: string) =>
    call<{ ok: true }>('git.discard', gitPayload(scope, worktree, { path })),
@@ -16,14 +16,13 @@ import { openSidebarFile } from '../intercept.tsx'
 import { EditorHost } from '../EditorHost.tsx'
 import { OpenWithSettings } from '../open-with-settings.tsx'
 import { lazyChunkComponent } from '../lazy-chunk.tsx'
-import { ChangesTab } from '../changes/ChangesTab.tsx'
-import { extractFileOps } from '../changes/ops.ts'
+import { ChangesTab, opCountOf } from '../changes/ChangesTab.tsx'
 import { DiffTab } from '../DiffTab.tsx'
 import { SubagentView } from '../SubagentView.tsx'
 import { consumeSidechatSeed, SideChatView, sidechatThreadIdOf } from '../SideChatView.tsx'
 import { api } from '../api.ts'
 import { BrowserView } from '../BrowserView.tsx'
-import { IconTerminalOutline16, IconDiffOutline16, IconGlobeOutline16 } from '../icons.tsx'
+import { IconTerminalOutline16, IconDiffOutline16, IconGlobeOutline16, IconFloatWindowOutline16, IconPanelBottomOutline16 } from '../icons.tsx'
 import { TERMINAL_FONT_SIZE_MAX, TERMINAL_FONT_SIZE_MIN } from '../../prefs-shared.ts'
 import type { ComponentType } from 'react'
 import type { SessionScope } from '../api.ts'
@@ -144,17 +143,42 @@ export function builtinTabs(ctx: Context, options: BuiltinTabOptions = {}): read
      // The unified changes tab (id kept as 'git' so persisted layouts keep
      // resolving): the Git lens is the former source-control panel; the
      // session lens is the former file-trace tab (PR #471). Both preview
-      // through one shared diff stack, and the badge counts this session's
-      // file ops (live from the event log — the git status itself needs a
-      // fetch, so it stays out of the badge).
+      // through one shared diff stack. The badge reads the op-count cache
+      // the tab's event poll publishes (the client ctx exposes no event
+      // log, and the git status needs a fetch — both stay out of the badge).
      id: 'git',
      title: () => t('changes'),
      icon: (size: number) => <IconDiffOutline16 size={size} />,
      order: 20,
      single: true,
-      badge: (ctx, scope) => {
-        const events = ctx.sessions.get(scope.sessionId)?.events
-        return events === undefined ? null : extractFileOps(events).length
+      badge: (_ctx, scope) => {
+        const count = opCountOf(scope.sessionId)
+        return count === undefined || count === 0 ? null : count
+      },
+      // Declarative settings: the diff-open picker (free window vs docked
+      // pane) renders as an iconed select row under the changes card's gear
+      // in the Side card settings page.
+      settings: {
+        toggles: [{
+          key: 'changesDiffFloat',
+          type: 'select',
+          title: () => t('changesDiffOpenTitle'),
+          desc: () => t('changesDiffOpenDesc'),
+          options: [
+            {
+              value: true,
+              icon: (size: number) => <IconFloatWindowOutline16 size={size} />,
+              title: () => t('changesDiffOpenFloat'),
+              desc: () => t('changesDiffOpenFloatDesc'),
+            },
+            {
+              value: false,
+              icon: (size: number) => <IconPanelBottomOutline16 size={size} />,
+              title: () => t('changesDiffOpenPane'),
+              desc: () => t('changesDiffOpenPaneDesc'),
+            },
+          ],
+        }],
      },
      component: ({ ctx, store, scope, tab, visible, onOpenFile, onOpenDiff }) => (
        <ChangesTab
@@ -3,23 +3,45 @@
 * (repository truth: staged/unstaged files, commit box, history) and the
 * session round (agent truth: every file the model read, wrote, or edited).
 * Both lenses preview their selections in a shared resizable bottom pane
- * ({@link DiffPane}); git targets can expand into the dedicated diff tab.
+ * ({@link DiffPane}); git targets expand into the dedicated diff tab —
+ * docked in a pane, or floated as a free window per the tab's setting.
 * The active lens and the pane height persist in the tab's meta, so the tab
 * reopens exactly where it was left.
+ *
+ * The session events ride the host's `changes.ops` route (the client
+ * runtime exposes no event-log face): the tab pulls the delta past its
+ * cursor while visible, folds it into ops, and publishes the op count to a
+ * module-level cache the tab-strip badge reads.
 */
-import { useState } from 'react'
+import { useCallback, useEffect, useRef, useState } from 'react'
+import type { SidebarSessionEvent } from '../../context-types.ts'
 import type { TabComponentProps } from '../service.ts'
 import { t } from '../locales.ts'
-import type { SidebarDiffRef } from '../state.ts'
+import { api } from '../api.ts'
+import { floatTab, type SidebarDiffRef } from '../state.ts'
 import { GitLens } from './GitLens.tsx'
 import { SessionLens } from './SessionLens.tsx'
 import { DiffPane, diffTabOf, type ChangesPreview } from './DiffPane.tsx'
-import type { FileOp } from './ops.ts'
+import { extractFileOps, knownContentBefore, type FileOp } from './ops.ts'
 import css from './changes.module.css'

 /** The default preview pane height (px) before the first drag. */
 const PANE_HEIGHT_DEFAULT = 300

+/** Cap on accumulated events: the lens shows the recent window, not eternity
+ *  (the host enforces the same bound per response). */
+const EVENTS_CAP = 4000
+
+/** Live op count per session: the tab's poller writes, the badge reads (a
+ *  badge cannot fetch — it must resolve synchronously during render). */
+const opCounts = new Map<string, number>()
+
+/** The session's traced-op count as of the last poll (undefined before the
+ *  tab has ever pulled; 0 hides the badge pill). */
+export function opCountOf(sessionId: string): number | undefined {
+  return opCounts.get(sessionId)
+}
+
 type Lens = 'git' | 'session'

 /** The persisted tab meta (JSON-serializable; rides the layout). */
@@ -36,6 +58,50 @@ export function ChangesTab({ ctx, store, scope, tab, visible, onOpenFile, onOpen
    typeof meta.previewH === 'number' && meta.previewH >= 140 ? meta.previewH : PANE_HEIGHT_DEFAULT,
  )

+  // ── Session-event accumulation: one pull on mount, then a 2.5s delta
+  //    poll while visible (paused otherwise; the next visible tick catches
+  //    up). The cursor is the last delivered seq, so each poll ships only
+  //    what the accumulator lacks. ────────────────────────────────────────
+  const eventsRef = useRef<readonly SidebarSessionEvent[]>([])
+  const seqRef = useRef(0)
+  const pollGen = useRef(0)
+  const [opsError, setOpsError] = useState(false)
+  const [tick, setTick] = useState(0)
+  const pull = useCallback(async (): Promise<void> => {
+    const generation = pollGen.current
+    try {
+      const { events, lastSeq } = await api.changesOps(scope, seqRef.current)
+      if (generation !== pollGen.current) return
+      if (events.length > 0) {
+        const merged = [...eventsRef.current, ...events]
+        eventsRef.current = merged.length > EVENTS_CAP ? merged.slice(merged.length - EVENTS_CAP) : merged
+      }
+      if (lastSeq > seqRef.current) seqRef.current = lastSeq
+      opCounts.set(scope.sessionId, extractFileOps(eventsRef.current).length)
+      setOpsError(false)
+      setTick(value => value + 1)
+    } catch {
+      // Offline / route unavailable: keep the last fold; surface it inline
+      // only while nothing has ever loaded.
+      if (generation === pollGen.current) setOpsError(true)
+    }
+  }, [scope.sessionId, scope.cwd])
+  useEffect(() => {
+    pollGen.current += 1
+    eventsRef.current = []
+    seqRef.current = 0
+    setOpsError(false)
+  }, [scope.sessionId])
+  useEffect(() => {
+    void pull()
+    if (!visible) return
+    const timer = window.setInterval(() => { void pull() }, 2_500)
+    return () => { window.clearInterval(timer) }
+  }, [visible, pull])
+  // tick only forces the re-render; the fold reads the ref directly.
+  void tick
+  const ops = extractFileOps(eventsRef.current)
+
  /** Persist a meta patch onto the tab (lens choice, pane height). */
  const patchMeta = (patch: ChangesMeta): void => {
    ctx.get('betterSidebar')?.updateTab(tab.id, {
@@ -55,8 +121,22 @@ export function ChangesTab({ ctx, store, scope, tab, visible, onOpenFile, onOpen
  }

  /** Preview one session op (with its best-effort prior content snapshot). */
-  const previewOp = (path: string, op: FileOp, prior: string | undefined): void => {
-    setPreview({ kind: 'op', path, op, prior })
+  const previewOp = (path: string, op: FileOp): void => {
+    setPreview({ kind: 'op', path, op, prior: knownContentBefore(ops, path, op) })
+  }
+
+  /** Expand the current git preview into the dedicated diff tab: docked
+   *  into the shell's diff pane, or floated as a free window centered on
+   *  the viewport when the tab's diff-open setting asks for it (default). */
+  const expandPreview = (): void => {
+    if (preview?.kind !== 'git') return
+    const diffTab = diffTabOf(preview.ref)
+    onOpenDiff?.(diffTab)
+    if (store.getPrefs().changesDiffFloat !== false) {
+      const x = Math.round(window.innerWidth / 2)
+      const y = Math.round(window.innerHeight / 2)
+      store.reduce(state => floatTab(state, diffTab.id, x, y))
+    }
  }

  const previewKey = (target: ChangesPreview): string => target.kind === 'git'
@@ -102,9 +182,8 @@ export function ChangesTab({ ctx, store, scope, tab, visible, onOpenFile, onOpen
        )
        : (
          <SessionLens
-            ctx={ctx}
-            scope={scope}
-            visible={visible}
+            ops={ops}
+            loadError={opsError && ops.length === 0}
            onPreview={previewOp}
            selectedCallId={preview !== null && preview.kind === 'op' ? preview.op.callId : null}
          />
@@ -117,9 +196,7 @@ export function ChangesTab({ ctx, store, scope, tab, visible, onOpenFile, onOpen
          height={paneHeight}
          onHeightCommit={(height) => { setPaneHeight(height); patchMeta({ previewH: height }) }}
          onClose={() => { setPreview(null) }}
-          onExpand={() => {
-            if (preview.kind === 'git') onOpenDiff?.(diffTabOf(preview.ref))
-          }}
+          onExpand={expandPreview}
        />
      )}
    </div>
@@ -12,8 +12,8 @@
 */
 import { useCallback, useEffect, useRef, useState, type MouseEvent, type ReactNode } from 'react'
 import {
-  Button, IconBranchOutline16, IconCodeOutline16, IconCopyOutline16, IconRefreshOutline16,
-  IconTrashOutline16, Input, Menu, Modal, writeClipboard,
+  Button, IconCodeOutline16, IconCopyOutline16, IconPlusOutline16,
+  IconRefreshOutline16, IconTrashOutline16, Input, Menu, Modal, writeClipboard,
 } from '@deepseek-ai/dsh-client-ui-primitives'
 import type { GitLogEntry, GitStatusEntry, GitStatusResult, GitWorktree, SessionScope } from '../api.ts'
 import { api } from '../api.ts'
@@ -418,7 +418,7 @@ export function GitLens(props: GitLensProps) {
          disabled={busy}
          onClick={() => { void stageEntry(entry, staged) }}
        >
-          {staged ? <IconTrashOutline16 /> : <IconBranchOutline16 />}
+          {staged ? <IconTrashOutline16 /> : <IconPlusOutline16 />}
        </button>
      </div>
    )
@@ -596,7 +596,7 @@ export function GitLens(props: GitLensProps) {
                : []),
              fileMenu?.staged === true
                ? { id: 'stage', label: t('unstage'), icon: <IconTrashOutline16 size={14} /> }
-                : { id: 'stage', label: t('stage'), icon: <IconBranchOutline16 size={14} /> },
+                : { id: 'stage', label: t('stage'), icon: <IconPlusOutline16 size={14} /> },
              ...(fileMenu !== null && !isUntracked(fileMenu.entry)
                ? [{ id: 'discard', label: t('discard'), icon: <IconTrashOutline16 size={14} />, danger: true }]
                : []),
@@ -1,62 +1,34 @@
 /**
 * The session lens of the changes tab: agent truth — every file the model
- * read, wrote, or edited in this session (folded from the session event
- * log), grouped by file, newest first, with kind filters. Clicking an op
- * previews it in the tab's shared bottom pane (see {@link DiffPane}): writes
- * and edits as line diffs, reads as a line-numbered content view, failures
- * as their real error text. Live `tool/call` / `tool/result` events append
- * while the tab is visible (bounded; paused and caught up when hidden).
+ * read, wrote, or edited in this session, grouped by file, newest first,
+ * with kind filters. Clicking an op previews it in the tab's shared bottom
+ * pane (see {@link DiffPane}): writes and edits as line diffs, reads as a
+ * line-numbered content view, failures as their real error text. The ops
+ * arrive pre-folded from the tab (which owns the event poll); this
+ * component is purely presentational.
 */
-import { useEffect, useMemo, useRef, useState, type ReactNode } from 'react'
-import type { SidebarSessionEvent } from '../../context-types.ts'
-import type { Context } from '../../context-types.ts'
-import type { SessionScope } from '../api.ts'
+import { useMemo, useState, type ReactNode } from 'react'
 import { relativeTime, t } from '../locales.ts'
-import { extractFileOps, groupByFile, knownContentBefore, type FileOp, type FileOpKind } from './ops.ts'
+import { groupByFile, type FileOp, type FileOpKind } from './ops.ts'
 import { formatBytes } from '../diff/rows.ts'
 import css from './changes.module.css'

-/** Cap on accumulated events: the lens shows the recent window, not eternity. */
-const EVENTS_CAP = 4000
-
 /** The op-kind filter chips: 'all' or one concrete kind. */
 type OpFilter = 'all' | FileOpKind

 export interface SessionLensProps {
-  ctx: Context
-  scope: SessionScope
-  /** Preview one op in the shared bottom pane (with its best-effort prior content). */
-  onPreview: (path: string, op: FileOp, prior: string | undefined) => void
+  /** The folded file operations, newest first (the tab's poll owns them). */
+  ops: readonly FileOp[]
+  /** Every poll failed and nothing loaded: an inline notice, not an empty
+   *  state that would read as "no operations". */
+  loadError: boolean
+  /** Preview one op in the shared bottom pane. */
+  onPreview: (path: string, op: FileOp) => void
  /** The op currently previewed (row highlight); null when the pane is closed. */
  selectedCallId: string | null
-  /** Fold events only while the tab is actually visible. */
-  visible: boolean
 }

-export function SessionLens({ ctx, scope, onPreview, selectedCallId, visible }: SessionLensProps) {
-  // The event log snapshot seeds the lens once; live tool/call and
-  // tool/result events append (bounded) and re-extract while visible.
-  const eventsRef = useRef<readonly SidebarSessionEvent[] | null>(null)
-  if (eventsRef.current === null) {
-    eventsRef.current = ctx.sessions.get(scope.sessionId)?.events ?? []
-  }
-  const [tick, setTick] = useState(0)
-  useEffect(() => {
-    if (typeof ctx.on !== 'function') return
-    const off = ctx.on('session/event', (session: unknown, event: SidebarSessionEvent) => {
-      const sessionId = (session as { id?: unknown } | null)?.id
-      if (sessionId !== scope.sessionId) return
-      if (event.type !== 'tool/call' && event.type !== 'tool/result') return
-      const list = [...eventsRef.current ?? [], event]
-      eventsRef.current = list.length > EVENTS_CAP ? list.slice(list.length - EVENTS_CAP) : list
-      if (visible) setTick(value => value + 1)
-    })
-    return () => { off() }
-  }, [ctx, scope.sessionId, visible])
-  // Becoming visible again catches up on events appended while paused.
-  useEffect(() => { if (visible) setTick(value => value + 1) }, [visible])
-
-  const ops = useMemo(() => extractFileOps(eventsRef.current ?? []), [tick])
+export function SessionLens({ ops, loadError, onPreview, selectedCallId }: SessionLensProps) {
  const [filter, setFilter] = useState<OpFilter>('all')
  const filteredOps = useMemo(
    () => (filter === 'all' ? ops : ops.filter(op => op.kind === filter)),
@@ -91,7 +63,8 @@ export function SessionLens({ ctx, scope, onPreview, selectedCallId, visible }:
        {chip('read', t('changesRead'), counts.get('read') ?? 0)}
      </div>
      <div className={css.sessionList}>
-        {ops.length === 0 && <div className={css.empty}>{t('changesSessionEmpty')}</div>}
+        {loadError && <div className={css.loadError}>{t('changesLoadError')}</div>}
+        {ops.length === 0 && !loadError && <div className={css.empty}>{t('changesSessionEmpty')}</div>}
        {ops.length > 0 && filteredOps.length === 0 && <div className={css.empty}>{t('changesFilterEmpty')}</div>}
        {[...groups.entries()].map(([path, fileOps]) => (
          <div key={path} className={css.fileGroup}>
@@ -104,19 +77,21 @@ export function SessionLens({ ctx, scope, onPreview, selectedCallId, visible }:
                data-op-kind={op.kind}
                data-op-error={op.isError ? 'true' : undefined}
                data-selected={selectedCallId === op.callId ? 'true' : undefined}
-                onClick={() => { onPreview(path, op, knownContentBefore(ops, path, op)) }}
+                onClick={() => { onPreview(path, op) }}
              >
                <span className={css.opKind} data-kind={op.kind}>
                  {t(op.kind === 'read' ? 'changesRead' : op.kind === 'write' ? 'changesWrite' : 'changesEdit')}
                </span>
-                <span className={css.opTime}>{relativeTime(new Date(op.time).toISOString())}</span>
                {op.running && <span className={css.opFlag}>{t('changesRunning')}</span>}
                {op.isError && <span className={css.opFlagError}>{t('changesError')}</span>}
-                {op.kind !== 'read' && !op.isError && (
-                  <span className={css.opSize}>
-                    {formatBytes(new Blob([op.edit?.newString ?? op.content ?? '']).size)}
-                  </span>
-                )}
+                <span className={css.opMeta}>
+                  {op.kind !== 'read' && !op.isError && (
+                    <span className={css.opSize}>
+                      {formatBytes(new Blob([op.edit?.newString ?? op.content ?? '']).size)}
+                    </span>
+                  )}
+                  <span className={css.opTime}>{relativeTime(new Date(op.time).toISOString())}</span>
+                </span>
              </button>
            ))}
          </div>
@@ -140,8 +140,9 @@
  color: var(--dsw-alias-label-secondary);
 }

-/* Status-letter tint: A added / D deleted / M·R modified / C·U conflicts. */
-.gitBadge[data-letter='A'] { color: var(--dsw-alias-state-success-primary); }
+/* Status-letter tint: A added / D deleted / M·R modified / C·U conflicts;
+   untracked '?' reads as a not-yet-added file, so it shares the added tint. */
+.gitBadge[data-letter='A'], .gitBadge[data-letter='?'] { color: var(--dsw-alias-state-success-primary); }
 .gitBadge[data-letter='D'] { color: var(--dsw-alias-state-error-primary); }
 .gitBadge[data-letter='M'], .gitBadge[data-letter='R'] { color: var(--dsw-alias-state-business-primary); }
 .gitBadge[data-letter='C'], .gitBadge[data-letter='U'] { color: var(--dsw-alias-state-warn-primary); }
@@ -316,19 +317,28 @@

 .sessionList { flex: 1; min-height: 0; overflow-y: auto; padding: 0 6px 10px; }
 .empty { color: var(--dsw-alias-label-tertiary); padding: 24px 8px; text-align: center; }
+.loadError { margin: 4px 8px; padding: 6px 10px; border-left: 3px solid var(--dsw-alias-state-warn-primary); border-radius: 0 6px 6px 0; color: var(--dsw-alias-label-secondary); font-size: 11px; }

-.fileGroup { margin-bottom: 8px; }
-.filePath { display: block; color: var(--dsw-alias-label-secondary); font-family: var(--ds-font-family-code, monospace); font-size: 11px; padding: 2px 4px; word-break: break-all; }
+.fileGroup { margin-bottom: 6px; }
+/* The group label sits between op blocks: extra head padding separates it from
+   the previous file's rows, the first group starts flush. */
+.filePath { display: block; color: var(--dsw-alias-label-tertiary); font-family: var(--ds-font-family-code, monospace); font-size: 11px; padding: 6px 4px 2px; word-break: break-all; }
+.fileGroup:first-child .filePath { padding-top: 2px; }
 .opRow { display: flex; align-items: center; gap: 6px; width: 100%; border: 0; border-radius: 6px; background: transparent; color: var(--dsw-alias-label-primary); font: inherit; font-size: 11px; padding: 3px 5px; cursor: pointer; text-align: left; }
 .opRow:hover { background: var(--dsw-alias-interactive-bg-hover); }
 .opRow[data-selected='true'] { background: var(--dsw-alias-interactive-bg-active); }
+/* A failed op carries a quiet error inset bar (the flag chip names it). */
+.opRow[data-op-error='true'] { box-shadow: inset 2px 0 0 var(--dsw-alias-state-error-primary); }
 .opKind { border-radius: 4px; font-size: 10px; line-height: 16px; padding: 0 5px; background: var(--dsw-alias-interactive-bg-hover); color: var(--dsw-alias-label-secondary); flex: none; }
 .opKind[data-kind='write'] { color: var(--dsw-alias-state-success-primary); }
 .opKind[data-kind='edit'] { color: var(--dsw-alias-state-business-primary); }
+/* Size + relative time ride as one right-aligned cluster so the kind chips
+   form a scannable left rail and the meta column stays flush right. */
+.opMeta { margin-left: auto; display: inline-flex; align-items: baseline; gap: 8px; flex: none; min-width: 0; }
 .opTime { color: var(--dsw-alias-label-tertiary); font-size: 10px; flex: none; }
 .opFlag { color: var(--dsw-alias-state-business-primary); font-size: 10px; flex: none; }
 .opFlagError { color: var(--dsw-alias-state-error-primary); font-size: 10px; flex: none; }
-.opSize { margin-left: auto; color: var(--dsw-alias-label-tertiary); font-size: 10px; flex: none; }
+.opSize { color: var(--dsw-alias-label-tertiary); font-size: 10px; flex: none; font-family: var(--ds-font-family-code, monospace); }

 /* ── Shared preview pane ───────────────────────────────────────────────── */

@@ -341,7 +351,10 @@
 .diffKind[data-kind='git'] { color: var(--dsw-alias-brand-primary); }
 .diffKind[data-kind='write'] { color: var(--dsw-alias-state-success-primary); }
 .diffKind[data-kind='edit'] { color: var(--dsw-alias-state-business-primary); }
-.diffPath { flex: 1; font-family: var(--ds-font-family-code, monospace); font-size: 11px; word-break: break-all; color: var(--dsw-alias-label-primary); min-width: 0; }
+/* The path keeps its tail (the file name is the identity; directories are
+   context): an RTL paragraph renders an ASCII path in reading order while
+   clipping its HEAD under the ellipsis. */
+.diffPath { flex: 1; direction: rtl; font-family: var(--ds-font-family-code, monospace); font-size: 11px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; color: var(--dsw-alias-label-primary); min-width: 0; }
 .diffStats { flex: none; display: inline-flex; gap: 5px; font-size: 10px; font-family: var(--ds-font-family-code, monospace); }

 .iconButton {
@@ -206,6 +206,7 @@ export function DiffRows({ segments, lang }: DiffRowsProps) {
      <div
        key={`fold-${String(segIndex)}`}
        className={css.foldRow}
+        data-expandable="true"
        data-expanded={isExpanded ? 'true' : undefined}
        onClick={() => {
          setExpandedFolds(prev => {
@@ -43,13 +43,18 @@
 .tokMacro { color: color-mix(in oklab, var(--dsw-alias-state-error-primary) 45%, var(--dsw-alias-state-business-primary)); }

 /* Hunk-fold row: collapsed marker chip; expanded padding drops to 0 so the
-   revealed rows keep the x-alignment of hunk rows (they carry their own). */
-.foldRow { padding: 0 10px; cursor: pointer; }
+   revealed rows keep the x-alignment of hunk rows (they carry their own).
+   Only an expandable fold (enough hidden rows to be worth a click) reads as
+   interactive — the › chevron matches the multi-file document's disclosure. */
+.foldRow { padding: 0 10px; }
+.foldRow[data-expandable='true'] { cursor: pointer; }
+.foldRow[data-expandable='true']:hover { background: var(--dsw-alias-interactive-bg-hover); }
 .foldRow[data-expanded='true'] { padding: 0; }
-.foldRow:hover { background: var(--dsw-alias-interactive-bg-hover); }
-.foldMarker { display: inline-block; padding: 2px 6px; border-radius: 4px; margin: 2px 0; color: var(--dsw-alias-label-tertiary); background: var(--dsw-alias-interactive-bg-hover); font-style: italic; }
 .foldRow[data-expanded='true'] { cursor: default; }
 .foldRow[data-expanded='true'] .foldMarker { display: none; }
+.foldMarker { display: inline-flex; align-items: center; gap: 5px; padding: 2px 7px; border-radius: 4px; margin: 2px 0; color: var(--dsw-alias-label-tertiary); background: var(--dsw-alias-interactive-bg-hover); }
+.foldRow[data-expandable='true'] .foldMarker { color: var(--dsw-alias-label-secondary); }
+.foldRow[data-expandable='true'] .foldMarker::before { content: '›'; color: var(--dsw-alias-label-tertiary); transition: transform var(--ds-transition-duration-slow) var(--ds-ease-in-out); }

 /* The huge-file overflow reveal under a capped hunk. */
 .expand { display: block; width: calc(100% - 20px); margin: 4px 10px; padding: 4px; border: 1px solid var(--dsw-alias-border-l1); border-radius: 6px; background: transparent; color: var(--dsw-alias-label-secondary); font: inherit; font-size: 11px; cursor: pointer; }
@@ -161,3 +161,15 @@ export const IconVscode16 = ({ size = 16, className }: IconProps) => (
    <path d="M23.15 2.587L18.21.21a1.494 1.494 0 0 0-1.705.29l-9.46 8.63-4.12-3.128a.999.999 0 0 0-1.276.057L.327 7.261A1 1 0 0 0 .326 8.74L3.899 12 .326 15.26a1 1 0 0 0 .001 1.479L1.65 17.94a.999.999 0 0 0 1.276.057l4.12-3.128 9.46 8.63a1.492 1.492 0 0 0 1.704.29l4.942-2.377A1.5 1.5 0 0 0 24 20.06V3.939a1.5 1.5 0 0 0-.85-1.352zm-5.146 14.861L10.826 12l7.178-5.448v10.896z" />
  </svg>
 )
+
+/**
+ * Free-window glyph in the app's outline style (1.5px stroke, currentColor):
+ * a background frame with a detached rounded mini-window floating over its
+ * top-right — the changes tab's "diff opens as a free window" setting.
+ */
+export const IconFloatWindowOutline16 = ({ size = 16, className }: IconProps) => (
+  <svg width={size} height={size} className={className} viewBox="0 0 16 16" fill="none" xmlns="http://www.w3.org/2000/svg">
+    <rect x="1.5" y="4.5" width="10" height="10" rx="2" stroke="currentColor" strokeWidth="1.5" />
+    <rect x="9.5" y="1.5" width="5" height="5" rx="1.5" stroke="currentColor" strokeWidth="1.5" fill="none" />
+  </svg>
+)
@@ -145,6 +145,13 @@ export const ar: Record<string, string> = {
  changesOpenDiffTab: 'فتح في تبويب diff منفصل',
  changesClosePreview: 'إغلاق المعاينة',
  changesResizePreview: 'تغيير حجم المعاينة',
+  changesDiffOpenTitle: 'يفتح الفرق كـ',
+  changesDiffOpenDesc: 'أين يضع إجراء «التوسيع إلى تبويب diff» الفرق',
+  changesDiffOpenFloat: 'نافذة عائمة',
+  changesDiffOpenFloatDesc: 'نافذة عائمة في وسط الشاشة — سحب وتحجيم وتثبيت فوق',
+  changesDiffOpenPane: 'لوحة',
+  changesDiffOpenPaneDesc: 'مثبتة أسفل اللوحة المصدر (تقسيم diff بنمط VSCode)',
+  changesLoadError: 'سجلات ملفات الجلسة غير متاحة الآن',
  staged: 'مُدرج',
  unstaged: 'غير مُدرج',
  cancel: 'إلغاء',
@@ -130,6 +130,13 @@ export const de: Record<string, string> = {
  changesOpenDiffTab: 'In eigenem Tab öffnen',
  changesClosePreview: 'Vorschau schließen',
  changesResizePreview: 'Vorschauhöhe anpassen',
+  changesDiffOpenTitle: 'Diff öffnet als',
+  changesDiffOpenDesc: 'Wo die Aktion „In eigenem Tab öffnen“ den Diff platziert',
+  changesDiffOpenFloat: 'Freies Fenster',
+  changesDiffOpenFloatDesc: 'Ein schwebendes Fenster mittig im Viewport — verschieben, skalieren, oben halten',
+  changesDiffOpenPane: 'Bereich',
+  changesDiffOpenPaneDesc: 'Unter dem Quellbereich angedockt (VSCode-artiger Diff-Split)',
+  changesLoadError: 'Sitzungsdatei-Aufzeichnungen sind derzeit nicht verfügbar',
  staged: 'Gestaged',
  unstaged: 'Nicht gestaged',
  cancel: 'Abbrechen',
@@ -137,6 +137,13 @@ export const fr: Record<string, string> = {
  changesOpenDiffTab: 'Ouvrir dans un onglet diff',
  changesClosePreview: 'Fermer l\'aperçu',
  changesResizePreview: 'Redimensionner l\'aperçu',
+  changesDiffOpenTitle: 'Le diff s\'ouvre en',
+  changesDiffOpenDesc: 'Où l\'action « Ouvrir dans un onglet diff » place le diff',
+  changesDiffOpenFloat: 'Fenêtre flottante',
+  changesDiffOpenFloatDesc: 'Une fenêtre flottante centrée sur la fenêtre — déplacer, redimensionner, garder au premier plan',
+  changesDiffOpenPane: 'Panneau',
+  changesDiffOpenPaneDesc: 'Ancré sous le panneau source (division de diff style VSCode)',
+  changesLoadError: 'Les enregistrements de fichiers de la session sont indisponibles',
  staged: 'En scène',
  unstaged: 'Hors scène',
  cancel: 'Annuler',
@@ -144,6 +144,13 @@ export const hi: Record<string, string> = {
  changesOpenDiffTab: 'अलग diff टैब में खोलें',
  changesClosePreview: 'पूर्वावलोकन बंद करें',
  changesResizePreview: 'पूर्वावलोकन का आकार बदलें',
+  changesDiffOpenTitle: 'diff खुलता है',
+  changesDiffOpenDesc: '«अलग diff टैब में खोलें» क्रिया diff को कहाँ रखती है',
+  changesDiffOpenFloat: 'मुक्त विंडो',
+  changesDiffOpenFloatDesc: 'व्यूपोर्ट के केंद्र में एक तैरती विंडो — खींचें, आकार बदलें, ऊपर रखें',
+  changesDiffOpenPane: 'पैनल',
+  changesDiffOpenPaneDesc: 'सोर्स पैनल के नीचे डॉक किया (VSCode-शैली diff स्प्लिट)',
+  changesLoadError: 'सेशन फ़ाइल रिकॉर्ड अभी अनुपलब्ध हैं',
  staged: 'स्टेज किया',
  unstaged: 'अनस्टेज',
  cancel: 'रद्द करें',
@@ -142,6 +142,13 @@ export const id: Record<string, string> = {
  changesOpenDiffTab: 'Buka di tab diff terpisah',
  changesClosePreview: 'Tutup pratinjau',
  changesResizePreview: 'Ubah ukuran pratinjau',
+  changesDiffOpenTitle: 'Diff terbuka sebagai',
+  changesDiffOpenDesc: 'Di mana aksi "buka di tab diff terpisah" menempatkan diff',
+  changesDiffOpenFloat: 'Jendela bebas',
+  changesDiffOpenFloatDesc: 'Jendela mengambang di tengah viewport — geser, ubah ukuran, selalu di atas',
+  changesDiffOpenPane: 'Panel',
+  changesDiffOpenPaneDesc: 'Ditambat di bawah panel sumber (split diff gaya VSCode)',
+  changesLoadError: 'Catatan berkas sesi sedang tidak tersedia',
  staged: 'Staged',
  unstaged: 'Unstaged',
  cancel: 'Batal',
@@ -135,6 +135,13 @@ export const it: Record<string, string> = {
  changesOpenDiffTab: 'Apri in una scheda diff',
  changesClosePreview: 'Ridimensiona l\'anteprima',
  changesResizePreview: 'Ridimensiona anteprima',
+  changesDiffOpenTitle: 'Il diff si apre come',
+  changesDiffOpenDesc: 'Dove l\'azione "apri in una scheda diff" colloca il diff',
+  changesDiffOpenFloat: 'Finestra libera',
+  changesDiffOpenFloatDesc: 'Una finestra flottante centrata sul viewport — trascina, ridimensiona, sempre in primo piano',
+  changesDiffOpenPane: 'Pannello',
+  changesDiffOpenPaneDesc: 'Ancorato sotto il pannello sorgente (divisione diff in stile VSCode)',
+  changesLoadError: 'I record dei file della sessione non sono disponibili',
  staged: 'In stage',
  unstaged: 'Non in stage',
  cancel: 'Annulla',
@@ -144,6 +144,13 @@ export const ja: Record<string, string> = {
  changesOpenDiffTab: '独立タブで開く',
  changesClosePreview: 'プレビューを閉じる',
  changesResizePreview: 'プレビューの高さを変更',
+  changesDiffOpenTitle: 'diff の展開先',
+  changesDiffOpenDesc: '「独立タブで開く」操作が diff をどこに配置するか',
+  changesDiffOpenFloat: 'フリーウィンドウ',
+  changesDiffOpenFloatDesc: 'ビューポート中央に浮かぶウィンドウ — ドラッグ・リサイズ・最前面固定',
+  changesDiffOpenPane: 'ペイン',
+  changesDiffOpenPaneDesc: 'ソースペインの下にドッキング（VSCode 式 diff 分割）',
+  changesLoadError: 'セッションのファイル記録は現在利用できません',
  staged: 'ステージ済み',
  unstaged: '未ステージ',
  cancel: 'キャンセル',
@@ -136,6 +136,13 @@ export const ko: Record<string, string> = {
  changesOpenDiffTab: '별도 탭에서 열기',
  changesClosePreview: '미리보기 닫기',
  changesResizePreview: '미리보기 높이 조정',
+  changesDiffOpenTitle: 'diff 열기 위치',
+  changesDiffOpenDesc: '「별도 탭에서 열기」 작업이 diff를 배치하는 곳',
+  changesDiffOpenFloat: '자유 창',
+  changesDiffOpenFloatDesc: '뷰포트 중앙의 떠 있는 창 — 드래그, 크기 조절, 항상 위',
+  changesDiffOpenPane: '패널',
+  changesDiffOpenPaneDesc: '소스 패널 아래에 도킹(VSCode 스타일 diff 분할)',
+  changesLoadError: '세션 파일 기록을 지금 사용할 수 없습니다',
  staged: '스테이징됨',
  unstaged: '스테이징 안 됨',
  cancel: '취소',
@@ -142,6 +142,13 @@ export const nl: Record<string, string> = {
  changesOpenDiffTab: 'In eigen diff-tabblad openen',
  changesClosePreview: 'Voorbeeld sluiten',
  changesResizePreview: 'Voorbeeld vergroten/verkleinen',
+  changesDiffOpenTitle: 'Diff opent als',
+  changesDiffOpenDesc: 'Waar de actie „in eigen diff-tabblad openen” de diff plaatst',
+  changesDiffOpenFloat: 'Vrij venster',
+  changesDiffOpenFloatDesc: 'Een zwevend venster in het midden — slepen, schalen, bovenop houden',
+  changesDiffOpenPane: 'Paneel',
+  changesDiffOpenPaneDesc: 'Vastgemaakt onder het bronpaneel (VSCode-achtige diff-split)',
+  changesLoadError: 'Sessiebestandsregistraties zijn nu niet beschikbaar',
  staged: 'Gestaged',
  unstaged: 'Niet gestaged',
  cancel: 'Annuleren',
@@ -146,6 +146,13 @@ export const pl: Record<string, string> = {
  changesOpenDiffTab: 'Otwórz w osobnej karcie',
  changesClosePreview: 'Zamknij podgląd',
  changesResizePreview: 'Zmień wysokość podglądu',
+  changesDiffOpenTitle: 'Diff otwiera się jako',
+  changesDiffOpenDesc: 'Gdzie akcja „otwórz w osobnej karcie” umieszcza diff',
+  changesDiffOpenFloat: 'Odrębne okno',
+  changesDiffOpenFloatDesc: 'Pływające okno wyśrodkowane na ekranie — przeciągaj, skaluj, trzymaj na wierzchu',
+  changesDiffOpenPane: 'Panel',
+  changesDiffOpenPaneDesc: 'Zadokowane pod panelem źródłowym (podział diff w stylu VSCode)',
+  changesLoadError: 'Zapisy plików sesji są teraz niedostępne',
  staged: 'W indeksie',
  unstaged: 'Poza indeksem',
  cancel: 'Anuluj',
@@ -127,6 +127,13 @@ export const pt: Record<string, string> = {
  changesOpenDiffTab: 'Abrir em uma aba de diff',
  changesClosePreview: 'Fechar prévia',
  changesResizePreview: 'Ajustar altura da prévia',
+  changesDiffOpenTitle: 'O diff abre como',
+  changesDiffOpenDesc: 'Onde a ação "abrir em uma aba de diff" coloca o diff',
+  changesDiffOpenFloat: 'Janela livre',
+  changesDiffOpenFloatDesc: 'Uma janela flutuante centralizada — arraste, redimensione, mantenha no topo',
+  changesDiffOpenPane: 'Painel',
+  changesDiffOpenPaneDesc: 'Ancorado abaixo do painel de origem (divisão de diff estilo VSCode)',
+  changesLoadError: 'Os registros de arquivos da sessão estão indisponíveis no momento',
  staged: 'Preparadas',
  unstaged: 'Não preparadas',
  cancel: 'Cancelar',
@@ -140,6 +140,13 @@ export const ru: Record<string, string> = {
  changesOpenDiffTab: 'Открыть в отдельной вкладке',
  changesClosePreview: 'Закрыть просмотр',
  changesResizePreview: 'Изменить высоту просмотра',
+  changesDiffOpenTitle: 'Diff открывается как',
+  changesDiffOpenDesc: 'Куда действие «открыть в отдельной вкладке» помещает diff',
+  changesDiffOpenFloat: 'Свободное окно',
+  changesDiffOpenFloatDesc: 'Плавающее окно по центру экрана — перетаскивание, масштаб, поверх всех',
+  changesDiffOpenPane: 'Панель',
+  changesDiffOpenPaneDesc: 'Прикреплено под исходной панелью (разделение diff в стиле VSCode)',
+  changesLoadError: 'Записи файлов сессии сейчас недоступны',
  staged: 'В индексе',
  unstaged: 'Не в индексе',
  cancel: 'Отмена',
@@ -127,6 +127,13 @@ export const sv: Record<string, string> = {
  changesOpenDiffTab: 'Öppna i egen diff-flik',
  changesClosePreview: 'Stäng förhandsvisning',
  changesResizePreview: 'Ändra storlek på förhandsvisningen',
+  changesDiffOpenTitle: 'Diff öppnas som',
+  changesDiffOpenDesc: 'Var åtgärden "öppna i egen diff-flik" placerar diffen',
+  changesDiffOpenFloat: 'Fritt fönster',
+  changesDiffOpenFloatDesc: 'Ett flytande fönster centrerat i vyn — dra, ändra storlek, håll överst',
+  changesDiffOpenPane: 'Panel',
+  changesDiffOpenPaneDesc: 'Dockad under källpanelen (VSCode-liknande diff-delning)',
+  changesLoadError: 'Sessionens filposter är inte tillgängliga just nu',
  staged: 'Köade',
  unstaged: 'Avköade',
  cancel: 'Avbryt',
@@ -144,6 +144,13 @@ export const th: Record<string, string> = {
  changesOpenDiffTab: 'เปิดในแท็บ diff แยก',
  changesClosePreview: 'ปิดตัวอย่าง',
  changesResizePreview: 'ปรับขนาดตัวอย่าง',
+  changesDiffOpenTitle: 'diff เปิดเป็น',
+  changesDiffOpenDesc: 'การกระทำ «เปิดในแท็บ diff แยก» วาง diff ไว้ที่ใด',
+  changesDiffOpenFloat: 'หน้าต่างลอย',
+  changesDiffOpenFloatDesc: 'หน้าต่างลอยกลางจอ — ลาก ย่อขยาย ปักหมุดไว้บนสุด',
+  changesDiffOpenPane: 'แพเนล',
+  changesDiffOpenPaneDesc: 'จอดใต้แพเนลต้นทาง (แยก diff สไตล์ VSCode)',
+  changesLoadError: 'บันทึกไฟล์ของเซสชันยังใช้ไม่ได้ตอนนี้',
  staged: 'Staged',
  unstaged: 'Unstaged',
  cancel: 'ยกเลิก',
@@ -144,6 +144,13 @@ export const tr: Record<string, string> = {
  changesOpenDiffTab: 'Ayrı bir diff sekmesinde aç',
  changesClosePreview: 'Önizlemeyi kapat',
  changesResizePreview: 'Önizlemeyi boyutlandır',
+  changesDiffOpenTitle: 'diff açılır',
+  changesDiffOpenDesc: '"Ayrı bir diff sekmesinde aç" eylemi diff\'i nereye koyar',
+  changesDiffOpenFloat: 'Serbest pencere',
+  changesDiffOpenFloatDesc: 'Görünümün ortasında yüzen pencere — sürükle, boyutlandır, üstte tut',
+  changesDiffOpenPane: 'Panel',
+  changesDiffOpenPaneDesc: 'Kaynak panelin altına sabitlenmiş (VSCode tarzı diff bölmesi)',
+  changesLoadError: 'Oturum dosya kayıtları şu anda kullanılamıyor',
  staged: 'Sahnelendi',
  unstaged: 'Sahnelenmedi',
  cancel: 'İptal',
@@ -144,6 +144,13 @@ export const vi: Record<string, string> = {
  changesOpenDiffTab: 'Mở trong tab diff riêng',
  changesClosePreview: 'Đóng xem trước',
  changesResizePreview: 'Điều chỉnh kích thước xem trước',
+  changesDiffOpenTitle: 'diff mở thành',
+  changesDiffOpenDesc: 'Hành động «mở trong tab diff riêng» đặt diff ở đâu',
+  changesDiffOpenFloat: 'Cửa sổ tự do',
+  changesDiffOpenFloatDesc: 'Cửa sổ nổi giữa khung nhìn — kéo, đổi kích thước, ghim trên cùng',
+  changesDiffOpenPane: 'Bảng',
+  changesDiffOpenPaneDesc: 'Gắn dưới bảng nguồn (chia diff kiểu VSCode)',
+  changesLoadError: 'Bản ghi tệp phiên hiện không khả dụng',
  staged: 'Đã stage',
  unstaged: 'Chưa stage',
  cancel: 'Hủy',
@@ -159,6 +159,13 @@ export const zhHK: Record<string, string> = {
  changesOpenDiffTab: '在獨立分頁中開啟',
  changesClosePreview: '關閉預覽',
  changesResizePreview: '調整預覽高度',
+  changesDiffOpenTitle: '差異展開方式',
+  changesDiffOpenDesc: '「展開為獨立分頁」把 diff 放到哪裡',
+  changesDiffOpenFloat: '浮動視窗',
+  changesDiffOpenFloatDesc: '作為自由視窗置中開啟，可拖拽、縮放、置頂',
+  changesDiffOpenPane: '面板',
+  changesDiffOpenPaneDesc: '停駐在來源面板下方（VSCode 式 diff 分欄）',
+  changesLoadError: '工作階段檔案記錄暫不可用',
  staged: '已暫存',
  unstaged: '未暫存',
  cancel: '取消',
@@ -159,6 +159,13 @@ export const zhMO: Record<string, string> = {
  changesOpenDiffTab: '在獨立分頁中開啟',
  changesClosePreview: '關閉預覽',
  changesResizePreview: '調整預覽高度',
+  changesDiffOpenTitle: '差異展開方式',
+  changesDiffOpenDesc: '「展開為獨立分頁」把 diff 放到哪裡',
+  changesDiffOpenFloat: '浮動視窗',
+  changesDiffOpenFloatDesc: '作為自由視窗置中開啟，可拖拽、縮放、置頂',
+  changesDiffOpenPane: '面板',
+  changesDiffOpenPaneDesc: '停駐在來源面板下方（VSCode 式 diff 分欄）',
+  changesLoadError: '工作階段檔案記錄暫不可用',
  staged: '已暫存',
  unstaged: '未暫存',
  cancel: '取消',
@@ -159,6 +159,13 @@ export const zhTW: Record<string, string> = {
  changesOpenDiffTab: '在獨立頁籤中開啟',
  changesClosePreview: '關閉預覽',
  changesResizePreview: '調整預覽高度',
+  changesDiffOpenTitle: '差異展開方式',
+  changesDiffOpenDesc: '「展開為獨立頁籤」把 diff 放到哪裡',
+  changesDiffOpenFloat: '浮動視窗',
+  changesDiffOpenFloatDesc: '作為自由視窗置中開啟，可拖拽、縮放、置頂',
+  changesDiffOpenPane: '面板',
+  changesDiffOpenPaneDesc: '停駐在來源面板下方（VSCode 式 diff 分欄）',
+  changesLoadError: '工作階段檔案記錄暫不可用',
  staged: '已暫存',
  unstaged: '未暫存',
  cancel: '取消',
@@ -150,6 +150,13 @@ export const zh = {
  changesOpenDiffTab: '在独立页签中打开',
  changesClosePreview: '关闭预览',
  changesResizePreview: '调整预览高度',
+  changesDiffOpenTitle: '差异展开方式',
+  changesDiffOpenDesc: '「展开为独立页签」把 diff 放到哪里',
+  changesDiffOpenFloat: '浮窗',
+  changesDiffOpenFloatDesc: '作为自由窗口居中打开，可拖拽、缩放、置顶',
+  changesDiffOpenPane: '面板',
+  changesDiffOpenPaneDesc: '停靠在源面板下方（VSCode 式 diff 分栏）',
+  changesLoadError: '会话文件记录暂不可用',
  staged: '已暂存',
  unstaged: '未暂存',
  cancel: '取消',
@@ -533,6 +540,13 @@ export const en: Record<keyof typeof zh, string> = {
  changesOpenDiffTab: 'Open in a diff tab',
  changesClosePreview: 'Close preview',
  changesResizePreview: 'Resize preview',
+  changesDiffOpenTitle: 'Diff opens as',
+  changesDiffOpenDesc: 'Where the "expand to a diff tab" action lands the diff',
+  changesDiffOpenFloat: 'Free window',
+  changesDiffOpenFloatDesc: 'A floating window centered on the viewport — drag, resize, keep on top',
+  changesDiffOpenPane: 'Pane',
+  changesDiffOpenPaneDesc: 'Docked below the source panel (VSCode-style diff split)',
+  changesLoadError: 'Session file records are unavailable right now',
  staged: 'Staged',
  unstaged: 'Unstaged',
  cancel: 'Cancel',
@@ -82,6 +82,9 @@ export function parsePrefs(value: unknown): SidebarPrefs {
    editorExplorer: typeof record.editorExplorer === 'boolean'
      ? record.editorExplorer
      : SIDEBAR_PREFS_DEFAULTS.editorExplorer,
+    changesDiffFloat: typeof record.changesDiffFloat === 'boolean'
+      ? record.changesDiffFloat
+      : SIDEBAR_PREFS_DEFAULTS.changesDiffFloat,
    workspaceFence: typeof record.workspaceFence === 'boolean'
      ? record.workspaceFence
      : SIDEBAR_PREFS_DEFAULTS.workspaceFence,
@@ -128,6 +128,7 @@ export const PrefsSchema: z<SidebarPrefs> = z.object({
  terminalFontSize: z.number().step(1).min(TERMINAL_FONT_SIZE_MIN).max(TERMINAL_FONT_SIZE_MAX).default(TERMINAL_FONT_SIZE_DEFAULT),
  interceptOpenPath: z.boolean().default(true),
  editorExplorer: z.boolean().default(false),
+  changesDiffFloat: z.boolean().default(true),
  workspaceFence: z.boolean().default(true),
  terminalShell: z.string().default(''),
  terminalShellArgs: z.string().default(''),
@@ -18,7 +18,7 @@ import { basename, dirname, extname, isAbsolute, join } from 'node:path'
 import type { IncomingMessage } from 'node:http'
 import type { Duplex } from 'node:stream'
 import { WebSocket, WebSocketServer } from 'ws'
-import type { Context, SidebarHttpRequest } from './context-types.ts'
+import type { Context, SidebarHttpRequest, SidebarSessionEvent } from './context-types.ts'
 import {
  Config,
  PrefsSchema,
@@ -455,6 +455,44 @@ function buildApi(
      const rev = requireString(payload, 'rev')
      return { content: await git.show(cwd, rev, path, repoRoot) }
    },
+    // The session's file-tool events for the changes tab's session lens
+    // (and its badge): the CLIENT runtime's sessions face has no event-log
+    // access, so the events cross the wire here — live session log first,
+    // the persisted logical log for not-yet-hydrated sessions. Only the
+    // two event types the lens folds are sent, narrowed to `seq > afterSeq`
+    // so polling is a small delta, with the same recent-window cap the
+    // client accumulator applies.
+    'changes.ops': async (payload) => {
+      const sessionId = requireString(payload, 'sessionId')
+      const rawAfter = (payload as { afterSeq?: unknown } | null)?.afterSeq
+      if (rawAfter !== undefined
+        && (typeof rawAfter !== 'number' || !Number.isSafeInteger(rawAfter) || rawAfter < 0)) {
+        throw new SidebarError('bad-request', 'afterSeq must be a non-negative integer')
+      }
+      // An absent cursor means "from the very first event" — a session whose
+      // log opens on a tool event (subagent seeds do) carries seq 0, which a
+      // literal `> 0` comparison would drop, so the absent case floors at -1.
+      const afterSeq = rawAfter ?? -1
+      let events: readonly SidebarSessionEvent[] | undefined = ctx.sessions.get(sessionId)?.events
+      if (events === undefined) {
+        const persistence = ctx.get('sessionPersistence')
+        if (persistence !== undefined) {
+          try {
+            events = (await persistence.inspect(sessionId)).events
+          } catch {
+            // Cold read unavailable (session never persisted): an empty
+            // window is the honest answer, not a wire error.
+          }
+        }
+      }
+      if (events === undefined) return { events: [], lastSeq: Math.max(afterSeq, 0) }
+      const CHANGES_EVENTS_CAP = 4000
+      const filtered = events.filter(
+        event => (event.type === 'tool/call' || event.type === 'tool/result') && event.seq > afterSeq,
+      )
+      const window = filtered.length > CHANGES_EVENTS_CAP ? filtered.slice(filtered.length - CHANGES_EVENTS_CAP) : filtered
+      return { events: window, lastSeq: window.at(-1)?.seq ?? afterSeq }
+    },
    // Release a terminal immediately. The WebSocket close frame already does
    // this while the socket is open; this route covers the tab-close that
    // happens while the socket is down (reconnect loop), so a closed tab can
@@ -77,6 +77,14 @@ export interface SidebarPrefs {
   * Side card settings; off restores the pre-merge editor exactly.
   */
  editorExplorer: boolean
+  /**
+   * Where the changes tab's "expand to a diff tab" action lands the diff:
+   * true (default) floats it as a free window centered on the viewport;
+   * false docks it into the shell's diff pane below the source panel (the
+   * pre-float behavior). The select lives under the changes card's gear in
+   * the Side card settings.
+   */
+  changesDiffFloat: boolean
  /**
   * Whether the sidebar's filesystem routes enforce the workspace fence:
   * every client-supplied path must resolve (through symlinks) inside the
@@ -267,6 +275,7 @@ export const SIDEBAR_PREFS_DEFAULTS: SidebarPrefs = {
  terminalFontSize: TERMINAL_FONT_SIZE_DEFAULT,
  interceptOpenPath: true,
  editorExplorer: false,
+  changesDiffFloat: true,
  workspaceFence: true,
  terminalShell: '',
  terminalShellArgs: '',
@@ -44,6 +44,20 @@ describe('built-in tab registrations', () => {
    expect(changes?.component).toBeDefined()
  })

+  it('the changes tab declares the diff-open picker (free window default)', () => {
+    const { service } = setup()
+    const toggles = service.getTab('git')?.settings?.toggles ?? []
+    expect(toggles.map(t => t.key)).toEqual(['changesDiffFloat'])
+    const picker = toggles[0]
+    expect(picker?.type).toBe('select')
+    expect(picker?.title).toBeDefined()
+    expect(picker?.desc).toBeDefined()
+    const options = picker?.options ?? []
+    // Float first (the default the reducer and prefs ship), pane second.
+    expect(options.map(o => o.value)).toEqual([true, false])
+    expect(options.every(o => o.icon !== undefined && o.title !== undefined && o.desc !== undefined)).toBe(true)
+  })
+
  it('only diff is hidden from the + menu; editor is the visible files window (order 10)', () => {
    const { service } = setup()
    expect(service.getTabs().filter(t => t.hidden).map(t => t.id)).toEqual(['diff'])
@@ -1,15 +1,16 @@
 /**
 * The unified changes tab shell: the lens switcher swaps the Git lens for
- * the session lens, and a Git-lens file row opens the shared preview pane
+ * the session lens, a Git-lens file row opens the shared preview pane
 * (loaded through the mocked git API, rendered by the shared DiffFiles
- * stack) instead of minting a diff tab directly.
+ * stack), and the session ops ride the mocked `changes.ops` poll — the
+ * event poll, the op fold and the badge cache all live in the tab.
 */
 // @vitest-environment jsdom
 import { afterEach, describe, expect, it, vi } from 'vitest'
 import { createElement } from 'react'
 import { createRoot, type Root } from 'react-dom/client'
 import { act } from 'react-dom/test-utils'
-import { ChangesTab } from '../src/client/changes/ChangesTab.tsx'
+import { ChangesTab, opCountOf } from '../src/client/changes/ChangesTab.tsx'
 import { createSidebarStore } from '../src/client/state.ts'
 import { api, type GitStatusResult, type GitWorktree } from '../src/client/api.ts'
 import type { Context } from '../src/context-types.ts'
@@ -19,16 +20,21 @@ import type { SidebarTab } from '../src/client/state.ts'

 const MAIN = 'C:/repo/main'

+/** One synthetic tool/call + tool/result pair (write of one file). */
+function writeEvents(seq: number, path: string): Array<{ type: string; seq: number; time: number; data: Record<string, unknown> }> {
+  return [
+    { type: 'tool/call', seq, time: seq, data: { name: 'write', callId: `w${seq}`, arguments: JSON.stringify({ file_path: path, content: 'body' }) } },
+    { type: 'tool/result', seq: seq + 1, time: seq + 1, data: { message: { source: { kind: 'tool', callId: `w${seq}` }, content: [{ type: 'tool-result', content: [{ type: 'text', text: 'ok' }] }] } } },
+  ]
+}
+
 function fakeContext(): Context {
  return {
-    sessions: { get: () => undefined },
    get: () => undefined,
-    on: () => () => { /* no-op */ },
  } as unknown as Context
 }

-function mount(root: Root): void {
-  const tab: SidebarTab = { id: 'git', type: 'git', title: 'Changes' }
+function mount(root: Root, tab: SidebarTab = { id: 'git', type: 'git', title: 'Changes' }): void {
  act(() => {
    root.render(createElement(ChangesTab, {
      ctx: fakeContext(),
@@ -108,21 +114,30 @@ describe('ChangesTab', () => {
    }
  })

-  it('switches to the session lens, which shows its empty state without ops', async () => {
+  it('folds the polled session events into session-lens rows and the badge cache', async () => {
    mockGit([])
+    const ops = vi.spyOn(api, 'changesOps')
+      .mockResolvedValue({ events: [...writeEvents(1, 'src/a.ts'), ...writeEvents(3, 'src/b.ts')], lastSeq: 4 })
+
    const container = document.createElement('div')
    document.body.append(container)
    const root: Root = createRoot(container)
    try {
      mount(root)
      await flushEffects()
+
+      // The tab pulled once on mount and published the op count.
+      expect(ops).toHaveBeenCalled()
+      expect(opCountOf('session')).toBe(2)
+
      const group = container.querySelector('[role="group"]')
-      expect(group).not.toBeNull()
      const buttons = [...group!.querySelectorAll<HTMLButtonElement>('button')]
      await act(async () => { buttons[1]!.click() })
-      // No session events in the fake context: the session lens empty state
-      // (locale-agnostic — the test env may resolve zh or en).
-      expect(container.textContent).toMatch(/本会话还没有文件操作|No file operations/)
+      // Two files grouped, newest first; the write chip carries its count.
+      expect(container.textContent).toContain('src/b.ts')
+      expect(container.textContent).toContain('src/a.ts')
+      const chips = [...container.querySelectorAll('button[aria-pressed]')]
+      expect(chips.some(chip => /写入\s*2|Write\s*2/.test(chip.textContent ?? ''))).toBe(true)
      // The git lens (its branch picker) is unmounted by the switch.
      expect(container.querySelector('select')).toBeNull()
    } finally {
@@ -97,6 +97,6 @@ describe('dsh-better-sidebar plugin export shape', () => {
    const overridden = (PrefsSchema as unknown as {
      (input: Record<string, unknown> | undefined): Record<string, unknown>
    })({ openByDefault: false, defaultWidthPercent: 45 })
-    expect(overridden).toEqual({ openByDefault: false, defaultWidthPercent: 45, autoOpenSubagent: true, autoOpenJobs: true, agentTerminalTools: false, agentOpenTools: false, bottomPanelAutoTerminal: true, terminalFontFamily: '', terminalFontSize: 13, interceptOpenPath: true, editorExplorer: false, workspaceFence: true, terminalShell: '', terminalShellArgs: '', titleBarCompat: false, titleBarStripPx: 40, htmlViewerNoSandbox: false, htmlViewerDefaultUnsafe: false, browserNoSandbox: false, browserInterceptLinks: true, browserInterceptHttp: true, browserInterceptHttps: false, browserAllowedLoopback: '', tabsEnabled: {}, viewersEnabled: {}, pluginSettings: {} })
+    expect(overridden).toEqual({ openByDefault: false, defaultWidthPercent: 45, autoOpenSubagent: true, autoOpenJobs: true, agentTerminalTools: false, agentOpenTools: false, bottomPanelAutoTerminal: true, terminalFontFamily: '', terminalFontSize: 13, interceptOpenPath: true, editorExplorer: false, workspaceFence: true, terminalShell: '', terminalShellArgs: '', titleBarCompat: false, titleBarStripPx: 40, htmlViewerNoSandbox: false, htmlViewerDefaultUnsafe: false, browserNoSandbox: false, browserInterceptLinks: true, browserInterceptHttp: true, browserInterceptHttps: false, browserAllowedLoopback: '', changesDiffFloat: true, tabsEnabled: {}, viewersEnabled: {}, pluginSettings: {} })
  })
 })
@@ -42,7 +42,7 @@ describe('side card preferences', () => {
        terminalFontFamily: '',
        terminalFontSize: 13,
        interceptOpenPath: true,
-        editorExplorer: false,
+        editorExplorer: false, changesDiffFloat: true,
        workspaceFence: true,
        terminalShell: '',
        terminalShellArgs: '',
@@ -76,7 +76,7 @@ describe('side card preferences', () => {
        terminalFontFamily: '',
        terminalFontSize: 13,
        interceptOpenPath: true,
-        editorExplorer: false,
+        editorExplorer: false, changesDiffFloat: true,
        workspaceFence: true,
        terminalShell: '',
        terminalShellArgs: '',
@@ -110,7 +110,7 @@ describe('side card preferences', () => {
        terminalFontFamily: '',
        terminalFontSize: 13,
        interceptOpenPath: true,
-        editorExplorer: false,
+        editorExplorer: false, changesDiffFloat: true,
        workspaceFence: true,
        terminalShell: '',
        terminalShellArgs: '',
@@ -282,9 +282,9 @@ describe('side card preferences', () => {
    const store = createSidebarStore()
    // Node environment: no window → the width falls back to PANEL_DEFAULT,
    // while the open flag still follows the preference.
-    store.setPrefs({ openByDefault: false, defaultWidthPercent: 45, autoOpenSubagent: true, autoOpenJobs: true, agentTerminalTools: false, agentOpenTools: false, bottomPanelAutoTerminal: true, terminalFontFamily: '', terminalFontSize: 13, interceptOpenPath: true, editorExplorer: true, workspaceFence: true, terminalShell: '', terminalShellArgs: '', titleBarScheme: 'auto', titleBarPresetId: '', customCss: '', titleBarCompat: false, titleBarStripPx: 40, htmlViewerNoSandbox: false, htmlViewerDefaultUnsafe: false, browserNoSandbox: false, browserInterceptLinks: true, browserInterceptHttp: true, browserInterceptHttps: false, browserAllowedLoopback: "", tabsEnabled: {}, viewersEnabled: {}, pluginSettings: {} })
+    store.setPrefs({ openByDefault: false, defaultWidthPercent: 45, autoOpenSubagent: true, autoOpenJobs: true, agentTerminalTools: false, agentOpenTools: false, bottomPanelAutoTerminal: true, terminalFontFamily: '', terminalFontSize: 13, interceptOpenPath: true, editorExplorer: true, changesDiffFloat: true, workspaceFence: true, terminalShell: '', terminalShellArgs: '', titleBarScheme: 'auto', titleBarPresetId: '', customCss: '', titleBarCompat: false, titleBarStripPx: 40, htmlViewerNoSandbox: false, htmlViewerDefaultUnsafe: false, browserNoSandbox: false, browserInterceptLinks: true, browserInterceptHttp: true, browserInterceptHttps: false, browserAllowedLoopback: "", tabsEnabled: {}, viewersEnabled: {}, pluginSettings: {} })
    store.setSession('fresh-session')
-    expect(store.getPrefs()).toEqual({ openByDefault: false, defaultWidthPercent: 45, autoOpenSubagent: true, autoOpenJobs: true, agentTerminalTools: false, agentOpenTools: false, bottomPanelAutoTerminal: true, terminalFontFamily: '', terminalFontSize: 13, interceptOpenPath: true, editorExplorer: true, workspaceFence: true, terminalShell: '', terminalShellArgs: '', titleBarScheme: 'auto', titleBarPresetId: '', customCss: '', titleBarCompat: false, titleBarStripPx: 40, htmlViewerNoSandbox: false, htmlViewerDefaultUnsafe: false, browserNoSandbox: false, browserInterceptLinks: true, browserInterceptHttp: true, browserInterceptHttps: false, browserAllowedLoopback: "", tabsEnabled: {}, viewersEnabled: {}, pluginSettings: {} })
+    expect(store.getPrefs()).toEqual({ openByDefault: false, defaultWidthPercent: 45, autoOpenSubagent: true, autoOpenJobs: true, agentTerminalTools: false, agentOpenTools: false, bottomPanelAutoTerminal: true, terminalFontFamily: '', terminalFontSize: 13, interceptOpenPath: true, editorExplorer: true, changesDiffFloat: true, workspaceFence: true, terminalShell: '', terminalShellArgs: '', titleBarScheme: 'auto', titleBarPresetId: '', customCss: '', titleBarCompat: false, titleBarStripPx: 40, htmlViewerNoSandbox: false, htmlViewerDefaultUnsafe: false, browserNoSandbox: false, browserInterceptLinks: true, browserInterceptHttp: true, browserInterceptHttps: false, browserAllowedLoopback: "", tabsEnabled: {}, viewersEnabled: {}, pluginSettings: {} })
    const snapshot = store.getSnapshot()
    expect(snapshot.sessionId).toBe('fresh-session')
    expect(snapshot.state?.panelOpen).toBe(false)
@@ -320,7 +320,7 @@ describe('side card preferences', () => {

  it('skips the default seed tab when the editor (files window) type is disabled', () => {
    const store = createSidebarStore()
-    store.setPrefs({ openByDefault: true, defaultWidthPercent: 30, autoOpenSubagent: true, autoOpenJobs: true, agentTerminalTools: false, agentOpenTools: false, bottomPanelAutoTerminal: true, terminalFontFamily: '', terminalFontSize: 13, interceptOpenPath: true, editorExplorer: true, workspaceFence: true, terminalShell: '', terminalShellArgs: '', titleBarScheme: 'auto', titleBarPresetId: '', customCss: '', titleBarCompat: false, titleBarStripPx: 40, htmlViewerNoSandbox: false, htmlViewerDefaultUnsafe: false, browserNoSandbox: false, browserInterceptLinks: true, browserInterceptHttp: true, browserInterceptHttps: false, browserAllowedLoopback: "", tabsEnabled: { editor: false }, viewersEnabled: {}, pluginSettings: {} })
+    store.setPrefs({ openByDefault: true, defaultWidthPercent: 30, autoOpenSubagent: true, autoOpenJobs: true, agentTerminalTools: false, agentOpenTools: false, bottomPanelAutoTerminal: true, terminalFontFamily: '', terminalFontSize: 13, interceptOpenPath: true, editorExplorer: true, changesDiffFloat: true, workspaceFence: true, terminalShell: '', terminalShellArgs: '', titleBarScheme: 'auto', titleBarPresetId: '', customCss: '', titleBarCompat: false, titleBarStripPx: 40, htmlViewerNoSandbox: false, htmlViewerDefaultUnsafe: false, browserNoSandbox: false, browserInterceptLinks: true, browserInterceptHttp: true, browserInterceptHttps: false, browserAllowedLoopback: "", tabsEnabled: { editor: false }, viewersEnabled: {}, pluginSettings: {} })
    store.setSession('no-editor')
    const state = store.getSnapshot().state!
    const tabs = allLeaves(state.splits).flatMap(leaf => leaf.tabs)
@@ -330,7 +330,7 @@ describe('side card preferences', () => {
    // editorExplorer modes.
    for (const editorExplorer of [true, false]) {
      const openStore = createSidebarStore()
-      openStore.setPrefs({ openByDefault: true, defaultWidthPercent: 30, autoOpenSubagent: true, autoOpenJobs: true, agentTerminalTools: false, agentOpenTools: false, bottomPanelAutoTerminal: true, terminalFontFamily: '', terminalFontSize: 13, interceptOpenPath: true, editorExplorer, workspaceFence: true, terminalShell: '', terminalShellArgs: '', titleBarScheme: 'auto', titleBarPresetId: '', customCss: '', titleBarCompat: false, titleBarStripPx: 40, htmlViewerNoSandbox: false, htmlViewerDefaultUnsafe: false, browserNoSandbox: false, browserInterceptLinks: true, browserInterceptHttp: true, browserInterceptHttps: false, browserAllowedLoopback: "", tabsEnabled: {}, viewersEnabled: {}, pluginSettings: {} })
+      openStore.setPrefs({ openByDefault: true, defaultWidthPercent: 30, autoOpenSubagent: true, autoOpenJobs: true, agentTerminalTools: false, agentOpenTools: false, bottomPanelAutoTerminal: true, terminalFontFamily: '', terminalFontSize: 13, interceptOpenPath: true, editorExplorer, changesDiffFloat: true, workspaceFence: true, terminalShell: '', terminalShellArgs: '', titleBarScheme: 'auto', titleBarPresetId: '', customCss: '', titleBarCompat: false, titleBarStripPx: 40, htmlViewerNoSandbox: false, htmlViewerDefaultUnsafe: false, browserNoSandbox: false, browserInterceptLinks: true, browserInterceptHttp: true, browserInterceptHttps: false, browserAllowedLoopback: "", tabsEnabled: {}, viewersEnabled: {}, pluginSettings: {} })
      openStore.setSession(`with-editor-${editorExplorer}`)
      const openTabs = allLeaves(openStore.getSnapshot().state!.splits).flatMap(leaf => leaf.tabs)
      expect(openTabs.map(tab => tab.type)).toEqual(['editor'])
@@ -340,7 +340,7 @@ describe('side card preferences', () => {
  it('seeds the empty editor home tab (files window) in both editorExplorer modes', () => {
    for (const editorExplorer of [true, false]) {
      const store = createSidebarStore()
-      store.setPrefs({ openByDefault: true, defaultWidthPercent: 30, autoOpenSubagent: true, autoOpenJobs: true, agentTerminalTools: false, agentOpenTools: false, bottomPanelAutoTerminal: true, terminalFontFamily: '', terminalFontSize: 13, interceptOpenPath: true, editorExplorer, workspaceFence: true, terminalShell: '', terminalShellArgs: '', titleBarScheme: 'auto', titleBarPresetId: '', customCss: '', titleBarCompat: false, titleBarStripPx: 40, htmlViewerNoSandbox: false, htmlViewerDefaultUnsafe: false, browserNoSandbox: false, browserInterceptLinks: true, browserInterceptHttp: true, browserInterceptHttps: false, browserAllowedLoopback: "", tabsEnabled: {}, viewersEnabled: {}, pluginSettings: {} })
+      store.setPrefs({ openByDefault: true, defaultWidthPercent: 30, autoOpenSubagent: true, autoOpenJobs: true, agentTerminalTools: false, agentOpenTools: false, bottomPanelAutoTerminal: true, terminalFontFamily: '', terminalFontSize: 13, interceptOpenPath: true, editorExplorer, changesDiffFloat: true, workspaceFence: true, terminalShell: '', terminalShellArgs: '', titleBarScheme: 'auto', titleBarPresetId: '', customCss: '', titleBarCompat: false, titleBarStripPx: 40, htmlViewerNoSandbox: false, htmlViewerDefaultUnsafe: false, browserNoSandbox: false, browserInterceptLinks: true, browserInterceptHttp: true, browserInterceptHttps: false, browserAllowedLoopback: "", tabsEnabled: {}, viewersEnabled: {}, pluginSettings: {} })
      store.setSession(`fresh-${editorExplorer}`)
      const tabs = allLeaves(store.getSnapshot().state!.splits).flatMap(leaf => leaf.tabs)
      expect(tabs).toHaveLength(1)
@@ -955,6 +955,7 @@ describe('side card settings routes', () => {
        browserInterceptHttp: true,
        browserInterceptHttps: false,
        browserAllowedLoopback: '',
+        changesDiffFloat: true,
        // The enable-switch maps default to {} (everything on).
        tabsEnabled: {},
        viewersEnabled: {},