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.

docs/cookbook/extension-cookbook.md

@@ -13,7 +13,7 @@ A tool registers on `ctx.tools`. The annotated `defineTool` example (typed `exec
 This permission gate is one example of a hook plugin. It returns a typed decision from the `tools/pre-execute` gate to allow or deny a call; sandbox, permission, and plan-mode plugins can use this extension point. Hook plugins can intercept other extension points and are not inherently permission gates. A "native hook" is an ordinary Cordis plugin on an interception point; it needs no external protocol.
 
 ```ts
-import type { Context } from 'cordis'
+import type { Context } from '@deepseek-ai/cordis'
 import type { PreToolDecision, ToolExecution } from '@deepseek-ai/dsh-tools'
 
 declare function isAllowed(exec: ToolExecution): Promise<boolean>
@@ -37,7 +37,7 @@ This waterfall is the reorderable policy layer. Use `ctx.tools.guard()` when an
 A UI plugin renders from the `session/event` feed (the assistant token stream as `assistant/chunk`, plus turn/step boundaries and tool activity), and drives input back in via `agent.followup()` / `agent.steer()`. A browser plugin contributing a business row to the built-in Web Client instead registers a `ConversationNodeDefinition` and keyed Chat renderer; follow the [Conversation Node guide](adding-a-conversation-node.md).
 
 ```ts
-import type { Context } from 'cordis'
+import type { Context } from '@deepseek-ai/cordis'
 import { createUserMessage } from '@deepseek-ai/dsh-llm'
 import { SessionId } from '@deepseek-ai/dsh-session'
 
@@ -67,7 +67,7 @@ A *protocol driver* adapts a wire peer to `ctx.agents`; it may serve a UI or an
 [`packages/acp/acp`](../../packages/acp/acp) is the automation-only worked example: it exposes fresh text sessions over Agent Client Protocol JSON-RPC stdio, emits committed assistant text, and registers a one-shot machine permission answerer for agents it owns. Its [README](../../packages/acp/acp/README.md) defines the exact methods, event order, and lifecycle contract.
 
 ```ts
-import type { Context } from 'cordis'
+import type { Context } from '@deepseek-ai/cordis'
 
 export const name = 'my-protocol-bridge'
 export const inject = ['agents', 'sessions', 'sessionPersistence']