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/client/web/src/seed.ts

@@ -10,7 +10,7 @@ import * as React from 'react'
 import * as ReactJsxRuntime from 'react/jsx-runtime'
 import * as ReactDom from 'react-dom'
 import * as ReactDomClient from 'react-dom/client'
-import * as Cordis from 'cordis'
+import * as Cordis from '@deepseek-ai/cordis'
 import * as UiSlots from '@deepseek-ai/dsh-client-ui-slots'
 import * as WebReact from '@deepseek-ai/dsh-client-web-react'
 import * as UiPrimitives from '@deepseek-ai/dsh-client-ui-primitives'
@@ -30,7 +30,7 @@ export function getStaticModules(): Record<string, unknown> {
     'react/jsx-runtime': ReactJsxRuntime,
     'react-dom': ReactDom,
     'react-dom/client': ReactDomClient,
-    'cordis': Cordis,
+    '@deepseek-ai/cordis': Cordis,
     '@deepseek-ai/dsh-client-ui-slots': UiSlots,
     '@deepseek-ai/dsh-client-web-react': WebReact,
     '@deepseek-ai/dsh-client-ui-primitives': UiPrimitives,