build(vendor): rescope the vendored Cordis packages into @deepseek-ai

Machine-produced by `pnpm run rescope-vendor --apply` plus the regeneration it
prints: `pnpm install` for the lockfile, `pnpm run gen-third-party-notices`,
`verify-translation-pairing --write` for the touched bilingual pairs,
`gen-doc-graphs`, and one typert snapshot whose ids embed character offsets.
`pnpm run rescope-vendor --check` verifies the result.

Renames nine vendored packages (cordis, cosmokit, schemastery and the six
@cordisjs plugins) and every reference that resolves them: manifest names and
dependency keys, module specifiers including declare-module merges, cordis.yml
plugin names, tsconfig paths, every Markdown fence, and `docs/` prose.
Directory names, upstream versions, and dependency ranges are unchanged, so
vendor/README.md still reads as an upstream snapshot; its manifest table gains
an upstream-name column so THIRD_PARTY_NOTICES keeps MIT attribution pointed
at each fork's origin.

The tutorial tier follows the rename end to end: its yaml fences named plugins
the Loader can no longer resolve, its `ts ignore-check` fences disagreed with
the compiled fences beside them, and its prose quoted both. The contracts that
told readers to keep upstream names — the root convention and the vendoring
cookbook's tree comment and manifest invariant — now say to rescope instead.

Two rules read `@deepseek-ai/` as "another workspace plugin": the client bundle
purity gate now names the vendored libraries a browser bundle inlines, and the
files where a bare `cordis` is an agent-preset id keep that product data.

docs/cordis-tutorial/04-events.zh.md

@@ -9,9 +9,9 @@
 创建 `stats.ts`，将它放在 `tmp/cordis-tutorial` 中。它是一项负责计数并在每次变化时发出通知的服务：
 
 ```ts
-import { Service, type Context } from 'cordis'
+import { Service, type Context } from '@deepseek-ai/cordis'
 
-declare module 'cordis' {
+declare module '@deepseek-ai/cordis' {
   interface Context {
     stats: StatsService
   }
@@ -46,7 +46,7 @@ export function apply(ctx: Context) {
 创建 `reporter.ts`：
 
 ```ts ignore-check
-import type { Context } from 'cordis'
+import type { Context } from '@deepseek-ai/cordis'
 import type {} from './stats.ts'
 
 export const name = 'reporter'
@@ -96,9 +96,9 @@ export function apply(ctx: Context) {
 waterfall 是实现拦截的模式。每个监听器都会收到参数和一个 `next()` continuation；它可以转换 `next()` 的返回值，也可以不调用 `next()` 就直接返回，从而短路链条的其余部分。Cordis 文档把后一种行为称为否决。创建 `waterfall-demo.ts`：
 
 ```ts
-import type { Context } from 'cordis'
+import type { Context } from '@deepseek-ai/cordis'
 
-declare module 'cordis' {
+declare module '@deepseek-ai/cordis' {
   interface Events {
     'demo/transform'(input: string, next: () => Promise<string>): Promise<string>
   }