fix(market): 移除公开版 cordis peer 并迁移类型基底到 @deepseek-ai/cordis

DSH 市场（dsh-community-market）预览硬拒依赖字段出现 'cordis'
（dependencies/peerDependencies/optionalDependencies 任一字段、
optional 均无效），导致 dshfind/1024Store 目录拿不到
repository_backlink 验证目标，点击安装报
"This catalog item has no verified install target"。

- package.json: 删除 cordis peer + peerDependenciesMeta；版本 0.15.2
- context-types.ts: Context 基底改 @deepseek-ai/cordis，结构服务面改
  交集（避免 DS host/client 对同一成员类型不同导致的 TS2717 merge
  冲突），仅保留 betterSidebar 的 module augmentation；删除
  declare module 'cordis'
- client/index.tsx: 4 处 effect 体失败分支改返回 no-op disposer
  （vendored cordis effect 契约拒绝 undefined 形状）
- 新增 tests/market-manifest.spec.ts：无 cordis 依赖字段、打包产物
  无生命周期脚本、bundle patch 安全路径、仓库身份、精确稳定版本
- 消费者检查扩展：@deepseek-ai/cordis 路径的 Context augmentation
  断言；文档示例同步迁移

src/index.ts

@@ -54,8 +54,10 @@ import { readJsonBody, requireString, SidebarError, writeError, writeJson, write
 
 export { Config }
 export type { SidebarConfig, ResolvedSidebarConfig }
-// Re-export the Context augmentation (declare module 'cordis') so consumers
-// `import type {} from 'dsh-better-sidebar'` and gain `ctx.betterSidebar`.
+// Re-export the Context augmentation (`declare module '@deepseek-ai/cordis'`)
+// so consumers `import type {} from 'dsh-better-sidebar'` and gain
+// `ctx.betterSidebar`; the Context re-export below is the vendored cordis
+// Context intersected with the structural service faces.
 // Also re-export the service descriptor types so consumers can type their
 // registerTab / registerFileViewer arguments without reaching into /client.
 export type { Context } from './context-types.ts'