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.

packages/code-runtime/code-runtime/src/index.ts

@@ -4,7 +4,7 @@
  * @module @deepseek-ai/dsh-code-runtime
  */
 
-import { Context, Service } from 'cordis'
+import { Context, Service } from '@deepseek-ai/cordis'
 import type { CodeRunRequest, CodeRunResult } from './types.ts'
 
 export type {
@@ -86,7 +86,7 @@ export const PORTABLE_RESERVED_WORDS: ReadonlySet<string> = new Set([
   'global', 'is', 'lambda', 'nonlocal', 'not', 'or', 'pass', 'raise', 'match', 'type', '_',
 ])
 
-declare module 'cordis' {
+declare module '@deepseek-ai/cordis' {
   interface Context {
     codeRuntime: CodeRuntime
   }