feat(editor): 文件树「在应用中打开」子菜单（外部编辑器/图钉固定/SSH 远端/自定义编辑器） (#334)

* feat(editor): file tree 'open with' submenu (external editors, pin, SSH-remote, custom editors)

The file tree right-click menu gains an 'Open with >' submenu with the
resource manager (reveal in file manager), VS Code, Cursor and Zed, plus
user-defined custom editors (name + URL template + VSCode-family flag).
Each submenu row carries a pushpin that promotes the target to a direct
top-level menu item.

A configurable SSH host (settings: Files card gear) switches VSCode-family
openers to <scheme>://vscode-remote/ssh-remote+<host>/<path> and hides
host-local targets (file manager / Zed / non-VSCode custom editors).

External opens run through the new fenced /sidebar/api/open.external route
which spawns the platform opener with an argv array (no shell); the client
never navigates raw scheme URLs itself. The settings seam's render panel now
appends after the declarative rows instead of replacing them.

* feat(editor): polish open-with menu UI — brand icons, pushpin, chevron, row alignment

- Submenu rows: the custom label is now a block-level flex row filling the
  primitives itemLabel, so the pushpin docks at the row's far right (matching
  the trailing check of every other menu); menu row icons normalized to 16px
  (DSH native menus use 16, ours were 14).
- The submenu parent row gains a right-aligned chevron (the primitives Menu
  renders no arrow for submenu parents).
- Icons via react-icons: codicons VscPin/VscPinned pushpins (replacing the
  hand-drawn pin), VscFile/VscFolder/VscFolderOpened tree glyphs (replacing
  the </> file mark), VscLinkExternal for the open-with parent and the
  browser tab's open-external button (globally), SiCursor/SiZedindustries
  brand silhouettes; the VS Code mark is inlined from simple-icons@11.0.0
  (CC0) as IconVscode16 since later simple-icons releases dropped it. All
  monochrome currentColor to follow the active skin.
- tsdown: pin react-icons si/vsc to their ESM entries via resolve.alias —
  the package's exports map lists require before import, so the shared
  conditionNames picked the unshakeable CJS entry and bloated the core
  bundle by ~6.4 MB; tree-shaken it now adds only ~12 KB.

src/client/EditorHost.tsx

@@ -22,7 +22,7 @@
  * The strategy dispatch is pure (planFirstMatch / planFsReadOutcome in
  * editor-load.ts); this component only wires it to the host APIs.
  */
-import { useCallback, useEffect, useRef, useState, useSyncExternalStore } from 'react'
+import { useCallback, useEffect, useMemo, useRef, useState, useSyncExternalStore } from 'react'
 import { createElement } from 'react'
 import clsx from 'clsx'
 import { IconCheckOutline16, IconFolderOpen16 } from '@deepseek-ai/dsh-client-ui-primitives'
@@ -33,6 +33,8 @@ import { planFirstMatch, planFsReadOutcome, type EditorLoadAction } from './edit
 import { baseName } from './FileTree.tsx'
 import { createFrameBatcher } from './frame-batcher.ts'
 import { openSidebarFile } from './intercept.tsx'
+import { openWithSshActive, openWithUrl, parseOpenWithConfig, resolveOpenWithTargets } from './open-with.ts'
+import { updatePluginSettings } from './plugin-settings.ts'
 import { TreePanel } from './TreePanel.tsx'
 import { t } from './locales.ts'
 import { relativeTo } from './paths.ts'
@@ -52,6 +54,10 @@ const TREE_WIDTH_DEFAULT = 240
 const TREE_WIDTH_MIN = 160
 const TREE_WIDTH_MAX = 480
 
+/** Stable empty blob for the editor pluginSettings read (a fresh `?? {}`
+ *  would change identity every snapshot and loop useSyncExternalStore). */
+const EMPTY_PLUGIN_BLOB: Record<string, unknown> = {}
+
 /** The tab's persisted meta object (a malformed meta reads as empty). */
 function metaOf(tab: SidebarTab): Record<string, unknown> {
   return tab.meta !== null && typeof tab.meta === 'object' && !Array.isArray(tab.meta)
@@ -106,6 +112,16 @@ export function EditorHost(props: {
     useCallback((callback: () => void) => store.subscribe(callback), [store]),
     useCallback(() => store.getSnapshot().prefs.editorExplorer, [store]),
   )
+  // The file tree's "open with" configuration (pluginSettings['editor']): a
+  // blob subscription, so a pin click or a settings-page edit re-renders the
+  // menu immediately. The parsed config also drives which targets are shown
+  // (SSH mode hides the host-local ones).
+  const editorBlob = useSyncExternalStore(
+    useCallback((callback: () => void) => store.subscribe(callback), [store]),
+    useCallback(() => store.getSnapshot().prefs.pluginSettings['editor'] ?? EMPTY_PLUGIN_BLOB, [store]),
+  )
+  const openWithConfig = useMemo(() => parseOpenWithConfig(editorBlob.openWith), [editorBlob])
+  const openWithTargets = useMemo(() => resolveOpenWithTargets(openWithConfig), [openWithConfig])
   // A path-less tab shows the empty-state hint in merged mode — and in split
   // mode it is the standalone explorer (tree-only, see the render below).
   const showEmpty = path === ''
@@ -150,6 +166,39 @@ export function EditorHost(props: {
     })
   }
 
+  /** The context menu's "open with" action: reveal the path in the OS file
+   *  manager, or hand the target's URL (a local `file` URL, or the SSH-remote
+   *  form for VSCode-family editors in remote mode) to the host's external
+   *  opener. Failures are logged only — a missing handler is the OS's
+   *  dialog, not a sidebar error. */
+  const openWith = (targetId: string, absolute: string): void => {
+    const target = openWithTargets.find(item => item.id === targetId)
+    if (target === undefined) return
+    if (target.kind === 'reveal') {
+      void api.openExternal({ action: 'reveal', path: absolute }).catch(
+        (error: unknown) => { console.error('open external failed', error) },
+      )
+      return
+    }
+    const url = openWithUrl(target, absolute, openWithConfig)
+    if (url === undefined) return
+    void api.openExternal({ action: 'url', url }).catch(
+      (error: unknown) => { console.error('open external failed', error) },
+    )
+  }
+
+  /** Toggle one target's pinned state. The write is serialized (see
+   *  plugin-settings.ts) and the menu re-renders when the store prefs land. */
+  const toggleOpenWithPin = (targetId: string): void => {
+    updatePluginSettings(store, 'editor', (blob) => {
+      const config = parseOpenWithConfig(blob.openWith)
+      const pinned = config.pinned.includes(targetId)
+        ? config.pinned.filter(id => id !== targetId)
+        : [...config.pinned, targetId]
+      return { ...blob, openWith: { ...config, pinned } }
+    })
+  }
+
   // The viewer's toolbar, hoisted into THIS header: the text editor reports
   // its state and registers its commands (both null/absent for viewers
   // without a toolbar — image, pdf, binary download).
@@ -287,6 +336,11 @@ export function EditorHost(props: {
           onOpenFile={openFile}
           onOpenFileNewTab={openFileNewTab}
           onOpenFileSide={openFileSide}
+          openWithTargets={openWithTargets}
+          openWithPinned={openWithConfig.pinned}
+          openWithSsh={openWithSshActive(openWithConfig)}
+          onOpenWith={openWith}
+          onToggleOpenWithPin={toggleOpenWithPin}
           onReferenceFile={onReferenceFile}
         />
       </div>
@@ -380,6 +434,11 @@ export function EditorHost(props: {
               onOpenFile={openFile}
               onOpenFileNewTab={openFileNewTab}
               onOpenFileSide={openFileSide}
+              openWithTargets={openWithTargets}
+              openWithPinned={openWithConfig.pinned}
+              openWithSsh={openWithSshActive(openWithConfig)}
+              onOpenWith={openWith}
+              onToggleOpenWithPin={toggleOpenWithPin}
               onReferenceFile={onReferenceFile}
             />
           </div>