feat(sidebar): 文件页与文件变动页 UIUX 重构 + 全局组件抽取

文件页（FileTree/TreePanel）
- Ctrl/Cmd 多选 + Shift 按可见行序连选（Esc/点空白/右键收敛），批量条支持复制路径、批量删除（共享 ConfirmDialog + 顺序 fsRemove）
- Git 变更着色：行名按状态上色 + M/A/D/U 徽标，目录按 dirHasChanges 着色，非仓库静默降级（数据来自共享 git 状态存储）
- 新建文件夹：fs.mkdir 路由 + mkdirWorkspaceEntry + 内联输入行（Enter/Esc/blur/IME 守卫）
- 性能：FileRow/DirRow memo（含反向验证）、搜索 hidden 停车不再卸载树、level 拉取世代守卫 + AbortController、fs.tree truncated 提示、use-dir-watch 入参 memo
- 拖拽上传视觉 token 化（硬编码色清零）；可见性下传后隐藏页签停止轮询
- 右键「打开方式」改为复用 DSH 自带 open-in-app（宿主探测的关联应用 + 文件管理器显示）

文件变动页（changes/diff）
- 36px 头（宿主 SegmentedControl）+ 单一 ChangeRow + SectionHeader 分组 + 吸底提交条单状态行 + 历史独立空态
- 修掉：双份空态、暂存失败 unhandled rejection、手动刷新被丢、仓库切换刷新两次、worktree 清单缺 repoRoot、工作树被自动切走、预览持旧快照、恢复高度未 clamp、session ops 无谓轮询
- DiffPane/DiffTab 共用 use-git-diff；修掉 DiffPane 的 untracked 预览从不渲染

全局组件与宿主接入
- 新增 src/client/ui（IconButton/Chip/SectionHeader/Notice/ConfirmDialog/StatusBadge + 共享 git 状态存储）
- 新增 src/client/open-in-app.ts（宿主 open-in-app 客户端适配），删除自研 open-with 全链路与 open.external 路由
- 客户端 inject 补 remote / remote.session：缺声明时 ctx.get('remote').session 会抛出并把整个面板打成错误条（真实挂载 lane 抓到）
- 词典：+25 键 / -20 openWith* / -noChanges，20 份同步

验证：typecheck / lint / test（126 文件 1322 通过）/ build 全绿；
DSH_CMD='npx -y --package @deepseek-ai/dsh@0.1.7-rc.1 dsh' pnpm test:mount 7/7 通过（含 tab sweep 与 perf lane）

src/client/open-with.ts

@@ -1,221 +0,0 @@
-/**
- * The file tree's "open with" vocabulary: which external editors / file
- * managers the context menu can hand a row's path to, how the per-user
- * configuration (custom editors, SSH host, pinned ids) is parsed out of the
- * persisted blob, and how the external URL is built (local `file` URLs and
- * VSCode-family SSH-remote URLs).
- *
- * Pure by design (no React / no `api`), so the whole surface is unit-testable
- * without a DOM or a host route. The menu and the settings panel only consume
- * the exported types and functions.
- */
-import type { CopyKey } from './locales.ts'
-
-/** One user-configured editor (persisted in `pluginSettings['editor'].openWith`). */
-export interface CustomEditor {
-  id: string
-  /** Human label shown in the menu (e.g. "Windsurf"). */
-  name: string
-  /** URL template with a `{path}` placeholder (e.g. `cursor://file/{path}`). */
-  urlTemplate: string
-  /** Whether the editor speaks the VSCode URL dialect — the only editors
-   *  with an SSH-remote form (`<scheme>://vscode-remote/ssh-remote+<host>/…`). */
-  isVscodeFamily: boolean
-}
-
-/** The per-user "open with" configuration (one key of the editor blob). */
-export interface OpenWithConfig {
-  /** SSH host (user@host or an ~/.ssh/config alias); '' = local workspace. */
-  sshHost: string
-  /** User-defined editors, appended after the built-ins. */
-  customEditors: CustomEditor[]
-  /** Ids of open-with targets pinned to the menu's top level
-   *  ('explorer' | 'vscode' | 'cursor' | 'zed' | 'custom:<id>'). */
-  pinned: string[]
-}
-
-/** One menu-visible open target (built-in or custom, SSH-filtered). */
-export interface OpenWithTarget {
-  /** Stable id (`explorer` / `vscode` / `cursor` / `zed` / `custom:<id>`). */
-  id: string
-  /** Locale key of a built-in label (custom editors carry `name` instead). */
-  nameKey?: CopyKey
-  /** User-defined label (custom editors only; '' for built-ins). */
-  name: string
-  /** 'reveal' = show in the OS file manager; 'url' = open a URL. */
-  kind: 'reveal' | 'url'
-  /** URL template with `{path}`; undefined for reveal targets. */
-  urlTemplate?: string
-  /** Whether the editor talks the VSCode URL dialect. */
-  isVscodeFamily: boolean
-  /** Hidden in SSH mode (a host-local opener cannot reach a remote path). */
-  localOnly: boolean
-}
-
-/** The default open-with configuration (fresh documents). */
-export const OPEN_WITH_DEFAULTS: OpenWithConfig = {
-  sshHost: '',
-  customEditors: [],
-  pinned: [],
-}
-
-/** The built-in open targets, in menu order. */
-export const OPEN_WITH_BUILTINS: readonly OpenWithTarget[] = [
-  {
-    id: 'explorer',
-    nameKey: 'openWithExplorer',
-    name: '',
-    kind: 'reveal',
-    isVscodeFamily: false,
-    localOnly: true,
-  },
-  {
-    id: 'vscode',
-    nameKey: 'openWithVscode',
-    name: '',
-    kind: 'url',
-    urlTemplate: 'vscode://file/{path}',
-    isVscodeFamily: true,
-    localOnly: false,
-  },
-  {
-    id: 'cursor',
-    nameKey: 'openWithCursor',
-    name: '',
-    kind: 'url',
-    urlTemplate: 'cursor://file/{path}',
-    isVscodeFamily: true,
-    localOnly: false,
-  },
-  {
-    id: 'zed',
-    nameKey: 'openWithZed',
-    name: '',
-    kind: 'url',
-    urlTemplate: 'zed://file/{path}',
-    isVscodeFamily: false,
-    localOnly: true,
-  },
-]
-
-/** Whether a persisted value makes a structurally valid custom-editor row.
- *  Name/template may be empty — the settings panel edits rows in place and
- *  an in-progress row must survive the round-trip; the MENU hides rows that
- *  fail the stricter {@link isValidCustomEditor} check. */
-function isCustomEditor(value: unknown): value is CustomEditor {
-  if (value === null || typeof value !== 'object' || Array.isArray(value)) return false
-  const record = value as Record<string, unknown>
-  return typeof record.id === 'string' && record.id !== ''
-    && typeof record.name === 'string'
-    && typeof record.urlTemplate === 'string'
-    && typeof record.isVscodeFamily === 'boolean'
-}
-
-/**
- * Parse the persisted `openWith` blob (tolerant): malformed fields fall back
- * to the defaults, malformed custom-editor rows are dropped, and pinned ids
- * are kept verbatim (unknown ids are pruned when the targets are resolved —
- * the menu is the only consumer of the resolved list).
- */
-export function parseOpenWithConfig(raw: unknown): OpenWithConfig {
-  if (raw === null || typeof raw !== 'object' || Array.isArray(raw)) return { ...OPEN_WITH_DEFAULTS }
-  const record = raw as Record<string, unknown>
-  const sshHost = typeof record.sshHost === 'string' ? record.sshHost : ''
-  const customEditors = Array.isArray(record.customEditors)
-    ? record.customEditors.filter(isCustomEditor)
-    : []
-  const pinned = Array.isArray(record.pinned)
-    ? record.pinned.filter((id): id is string => typeof id === 'string' && id !== '')
-    : []
-  return { sshHost, customEditors, pinned }
-}
-
-/** Whether a custom editor id belongs to this config (id prefix match). */
-function customIdOf(id: string): string {
-  return `custom:${id}`
-}
-
-/**
- * The menu-visible open targets, in order (built-ins then custom editors).
- * In SSH mode the local-only targets (the OS file manager, Zed, custom
- * editors without the VSCode dialect) are dropped — they cannot reach a
- * remote path. Unknown pinned ids are pruned here too.
- */
-export function resolveOpenWithTargets(config: OpenWithConfig): OpenWithTarget[] {
-  const ssh = config.sshHost.trim() !== ''
-  const targets: OpenWithTarget[] = [
-    ...OPEN_WITH_BUILTINS,
-    ...config.customEditors
-      .filter(isValidCustomEditor)
-      .map((editor): OpenWithTarget => ({
-        id: customIdOf(editor.id),
-        name: editor.name,
-        kind: 'url',
-        urlTemplate: editor.urlTemplate,
-        isVscodeFamily: editor.isVscodeFamily,
-        localOnly: !editor.isVscodeFamily,
-      })),
-  ]
-  return targets.filter(target => !(ssh && target.localOnly))
-}
-
-/** The SSH hint appended to a target's label in remote mode. */
-export function openWithSshActive(config: OpenWithConfig): boolean {
-  return config.sshHost.trim() !== ''
-}
-
-/**
- * The URL to open for one resolved target, or undefined when the target has
- * no URL form (reveal) or the template is malformed. The path is inserted
- * RAW into the template (browsers percent-encode as needed; VSCode-family
- * URL parsers consume the absolute path with its leading slash, e.g.
- * `vscode://file//home/u/f.ts` or `vscode://file/C:/Users/u/f.ts`).
- */
-export function openWithUrl(target: OpenWithTarget, path: string, config: OpenWithConfig): string | undefined {
-  if (target.kind !== 'url' || target.urlTemplate === undefined) return undefined
-  const normalized = normalizeUrlPath(path)
-  const ssh = openWithSshActive(config)
-  if (ssh && target.isVscodeFamily) {
-    const scheme = schemeOf(target.urlTemplate)
-    if (scheme === undefined) return undefined
-    // `ssh-remote+<host>` owns NO slash of its own: the path keeps its
-    // leading slash, so `/home/u/f.ts` lands as `…+host/home/u/f.ts`.
-    return `${scheme}://vscode-remote/ssh-remote+${config.sshHost.trim()}${normalized}`
-  }
-  if (!target.urlTemplate.includes('{path}') || !hasUrlScheme(target.urlTemplate)) return undefined
-  return target.urlTemplate.replace('{path}', normalized)
-}
-
-/** Whether a template starts with a `scheme://` prefix (the only shape the
- *  host's external opener accepts and the settings panel suggests). */
-function hasUrlScheme(template: string): boolean {
-  return /^[a-z][a-z0-9+.-]*:\/\//i.test(template)
-}
-
-/** The scheme of a URL template (the part before the first ':'), or undefined. */
-function schemeOf(template: string): string | undefined {
-  const at = template.indexOf(':')
-  if (at <= 0) return undefined
-  const scheme = template.slice(0, at)
-  return /^[a-z][a-z0-9+.-]*$/i.test(scheme) ? scheme : undefined
-}
-
-/** Normalize a filesystem path for embedding in a URL (backslashes → '/'). */
-export function normalizeUrlPath(path: string): string {
-  return path.replace(/\\/g, '/')
-}
-
-/** A fresh custom-editor id (uuid when available, time-based fallback). */
-export function newCustomEditorId(): string {
-  if (typeof crypto !== 'undefined' && typeof crypto.randomUUID === 'function') {
-    return crypto.randomUUID()
-  }
-  return `${Date.now().toString(36)}${Math.random().toString(36).slice(2)}`
-}
-
-/** Validate one custom-editor row before the settings panel accepts it. */
-export function isValidCustomEditor(row: { name: string; urlTemplate: string }): boolean {
-  return row.name.trim() !== ''
-    && row.urlTemplate.includes('{path}')
-    && /^[a-z][a-z0-9+.-]*:\/\//i.test(row.urlTemplate.trim())
-}