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.

scripts/publish-npm-baseline.ts

@@ -258,7 +258,9 @@ class WorkspacePackageSet {
       const name = expectString(manifest, 'name', manifestPath)
       const version = expectString(manifest, 'version', manifestPath)
       const isVendored = manifestPath.startsWith('vendor/')
-      if (!isVendored && !name.startsWith('@deepseek-ai/')) {
+      // Vendored packages are rescoped too (vendor/README.md), so publication
+      // never carries an upstream name that would squat it on the registry.
+      if (!name.startsWith('@deepseek-ai/')) {
         throw new Error(`${manifestPath} must name an @deepseek-ai package`)
       }
       if (name === '@deepseek-ai/dsh-root') {