feat(file-icons): FileIconDescriptor 支持 names / folderNames 与 open 参数

图标主题（VSCode 的 fileNames / folderNames 半边）需要按**文件名**和**目录名**
着色，扩展名规则表达不了 `package.json` / `Dockerfile` / `node_modules`。

- `names?: readonly string[]`：精确 basename（大小写不敏感），命中优先于扩展名。
- `folderNames?: readonly string[]`：精确目录 basename，命中优先于保留扩展名；
  只认领列出的目录，未列出的目录仍走 `'folder'`/`'folder-open'` 或内置 glyph。
- `exts` 变为可选：省略 = 没有扩展名规则（`names`-only 注册不再是 catch-all）；
  `exts: []` 仍是全局默认 catch-all，语义不变。
- `icon(path, size, open?)`：目录行的展开态传入工厂，一条注册即可渲染开/合两态。
- `matchFileIcon` 先 names 后 exts；`matchFolderIcon(open, name?)` 先 folderNames
  后保留扩展名（新参数可选，旧调用不变）。
- 指南 §7 同步：字段、匹配顺序、四例注册（names / folderNames / 全目录 / catch-all）。

测试：`tests/file-icons.spec.tsx` 19 → 23（names 大小写、name 优先于 ext、
folderNames 只认领列出目录、open 传入工厂）；`tests/consumer-types.ts` 补新字段。

tests/consumer-types.ts

@@ -132,9 +132,11 @@ service.openFile({ sessionId: 's1', cwd: '/p' }, '/p/a.csv', 'Data')
 const icon: FileIconDescriptor = {
   id: 'my-plugin:icons',
   exts: ['csv', FOLDER_EXT, FOLDER_OPEN_EXT],
+  names: ['package.json'],
+  folderNames: ['node_modules'],
   priority: 5,
-  icon: (path: string, size: number) => {
-    void path; void size
+  icon: (path: string, size: number, open?: boolean) => {
+    void path; void size; void open
     return null
   },
 }
@@ -142,6 +144,7 @@ service.registerFileIcon(icon)
 service.getFileIcons()
 service.matchFileIcon('/p/a.csv')
 service.matchFolderIcon(true)
+service.matchFolderIcon(true, 'node_modules')
 service.fileIcon('/p/a.csv', 14)
 service.folderIcon('/p', true, 14)
 

tests/file-icons.spec.tsx

@@ -172,6 +172,57 @@ describe('fileIcon resolver chain (specific → builtin → catch-all → VscFil
   })
 })
 
+describe('name matching (names / folderNames — the icon-theme half)', () => {
+  it('a names rule claims the exact basename, case-insensitively', () => {
+    const service = createBetterSidebarService(createSidebarStore())
+    service.registerFileIcon({ id: 'npm', names: ['package.json'], icon: marker })
+    expect(service.matchFileIcon('/w/package.json')?.id).toBe('npm')
+    expect(service.matchFileIcon('/w/Package.JSON')?.id).toBe('npm')
+    expect(service.matchFileIcon('/w/pkg.json')).toBeUndefined()
+  })
+
+  it('a name rule outranks an extension rule and the built-in glyph', () => {
+    const service = createBetterSidebarService(createSidebarStore())
+    service.registerFileIcon({ id: 'by-ext', exts: ['json'], icon: markerB })
+    service.registerFileIcon({ id: 'by-name', names: ['package.json'], icon: marker })
+    expect(service.matchFileIcon('/w/package.json')?.id).toBe('by-name')
+    expect(glyphOf(service.fileIcon('/w/package.json', 14))).toBe('span')
+    // Other json files still take the extension rule.
+    expect(glyphOf(service.fileIcon('/w/tsconfig.json', 14))).toBe('b')
+  })
+
+  it('a folderNames rule claims only the directories it names, and outranks the reserved exts', () => {
+    const service = createBetterSidebarService(createSidebarStore())
+    service.registerFileIcon({ id: 'all-dirs', exts: ['folder', 'folder-open'], icon: markerB })
+    service.registerFileIcon({ id: 'named', folderNames: ['node_modules'], icon: marker })
+    expect(service.matchFolderIcon(false, 'node_modules')?.id).toBe('named')
+    expect(service.matchFolderIcon(false, 'NODE_MODULES')?.id).toBe('named')
+    // An unnamed directory still takes the reserved-ext registration.
+    expect(service.matchFolderIcon(false, 'src')?.id).toBe('all-dirs')
+    // A descriptor with folderNames only never claims unnamed directories.
+    const solo = createBetterSidebarService(createSidebarStore())
+    solo.registerFileIcon({ id: 'named', folderNames: ['src'], icon: marker })
+    expect(solo.matchFolderIcon(false, 'lib')).toBeUndefined()
+    expect(glyphOf(solo.folderIcon('/w/lib', false, 14))).toBe(VscFolder)
+  })
+
+  it('the folder factory receives the open flag so one descriptor renders both states', () => {
+    const service = createBetterSidebarService(createSidebarStore())
+    const seen: (boolean | undefined)[] = []
+    service.registerFileIcon({
+      id: 'stateful',
+      folderNames: ['src'],
+      icon: (_path, _size, open) => {
+        seen.push(open)
+        return open === true ? marker() : markerB()
+      },
+    })
+    expect(glyphOf(service.folderIcon('/w/src', false, 14))).toBe('b')
+    expect(glyphOf(service.folderIcon('/w/src', true, 14))).toBe('span')
+    expect(seen).toEqual([false, true])
+  })
+})
+
 describe('folderIcon resolver (registered folder/folder-open → builtin glyphs)', () => {
   it('unregistered directories show the builtin glyphs', () => {
     const service = createBetterSidebarService(createSidebarStore())