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/gen-cordis-catalog.ts

@@ -99,7 +99,7 @@ export const SERVICE_PAGE: Record<string, string> = {
 /**
  * Context keys declared in `interface Context` merges that the rendering
  * projection cannot see, each with the reason and its documentation owner.
- * The scan that enforces this list reads EVERY `declare module 'cordis'`
+ * The scan that enforces this list reads EVERY `declare module '@deepseek-ai/cordis'`
  * Context merge under `packages/x/x/src/**` — any depth, not only root
  * `index.ts` files with a same-named service class — so a new service can
  * never silently join this blind spot: it either enters {@link SERVICE_PAGE}
@@ -168,7 +168,7 @@ export const EVENT_SCOPE_PAGE: Record<string, string> = {
  * Event names declared in `interface Events` merges that the rendering
  * projection cannot see, each with the reason and its documentation owner.
  * The mirror of {@link SERVICE_WALK_EXEMPTIONS} for events: an independent
- * scan reads EVERY `declare module 'cordis'` Events merge under
+ * scan reads EVERY `declare module '@deepseek-ai/cordis'` Events merge under
  * `packages/x/x/src/**`, so a declared event either renders onto a subsystems
  * page (via {@link EVENT_SCOPE_PAGE}) or names itself here — never vanishes
  * silently. Keys are full event names, not scopes: client-face events share