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-third-party-notices.spec.ts

@@ -134,13 +134,17 @@ describe('parseVendoredRows', () => {
     const rows = parseVendoredRows(readFileSync(resolve(root, 'vendor/README.md'), 'utf8'))
 
     expect(rows.length).toBeGreaterThan(0)
-    expect(rows).toContainEqual({ npmName: 'cordis', upstream: 'https://github.com/cordiverse/cordis' })
+    expect(rows).toContainEqual({
+      npmName: '@deepseek-ai/cordis',
+      upstreamName: 'cordis',
+      upstream: 'https://github.com/cordiverse/cordis',
+    })
     // The upstream column carries a trailing package path for some rows; it is not part of the URL.
     expect(rows.every(row => /^https:\/\/\S+$/.test(row.upstream))).toBe(true)
   })
 
   it('yields nothing when the table columns change, so the generator fails loud', () => {
-    expect(parseVendoredRows('| `cordis/` | cordis | 4.0.0 | https://example.com | `abc123` |\n')).toEqual([])
+    expect(parseVendoredRows('| `cordis/` | `@deepseek-ai/cordis` | cordis | 4.0.0 | https://example.com | `abc123` |\n')).toEqual([])
   })
 
   it('covers every vendored directory, so no package can drop out of the notices', () => {