chore(release): 0.15.1 (#324)

* chore(release): 0.15.1

- bump version: package.json / dsh.plugin.json / SIDEBAR_SERVICE_VERSION
- README / README_EN: add v0.15.1 changelog (sidechat Codex-style transcript
  rework, terminal park-frame pty keep-alive, file-tree drag gating, README
  rewrite); plugin ecosystem 28+ with two new entries
  (dsh-better-sidebar-starter, my-dsh-plugins) and per-category <details>
  collapsible listings

* docs(readme): add community section placeholder for WeChat/QQ group QR codes

dsh.plugin.json

@@ -1,6 +1,6 @@
 {
   "id": "dsh-external/dsh-better-sidebar",
-  "version": "0.15.0",
+  "version": "0.15.1",
   "main": "./lib/index.js",
   "description": "VSCode 风格右侧侧边栏：文件资源管理器 / 编辑器 / 终端 / Git / 浏览器，按会话隔离。暴露服务供其他插件注册侧边栏页面和文件预览器",
   "engines": {