test(sdk): snapshot suite over the SDK path; docs for the SDK stack

- examples/jsonrpc-agent gains its first snapshot suite (sdk.snapshot.ts):
  the real dsh-jsonrpc-agent runtime driven through the real dsh-sdk-client,
  keyless llm-replay behind a new cordis.snapshot.yml overlay; three recorded
  scenarios (text turn, bash tool, spawn subagent) pin the notification
  stream, the SDK turn result, and the persisted parent+child session logs.
- Bilingual READMEs for dsh-sdk-protocol / dsh-sdk-client / dsh-subagent-sdk;
  sdk/ and subagent/ group tables extended; dsh-jsonrpc README points at the
  extracted protocol package; Agent Note (en+zh) owns the decision.
- The proposed make-jsonrpc-directional note is updated for the transport's
  new home and its second (client) consumer.
- Model Experience sentence allowlist entries for the two client-side
  packages; module graph + config catalog regenerated; i18n pairings
  recorded. doc-sync passes 24/24.

docs/config-catalog.md

@@ -555,7 +555,7 @@ export interface JsonRpcConfig {
 
 Depends on: `Readable` (`node:stream`) · `Writable` (`node:stream`)
 
-Source: [`packages/ui/jsonrpc/src/index.ts:26`](../packages/ui/jsonrpc/src/index.ts)
+Source: [`packages/ui/jsonrpc/src/index.ts:25`](../packages/ui/jsonrpc/src/index.ts)
 
 ## `@deepseek-ai/dsh-llm-deepseek`
 
@@ -1330,7 +1330,7 @@ export interface Config {
 export type PermissionPolicy = 'allow' | 'reject'
 ```
 
-Source: [`packages/subagent/subagent-acp/src/index.ts:21`](../packages/subagent/subagent-acp/src/index.ts)
+Source: [`packages/subagent/subagent-acp/src/index.ts:20`](../packages/subagent/subagent-acp/src/index.ts)
 
 ## `@deepseek-ai/dsh-subagent-fork`
 
@@ -1346,6 +1346,55 @@ export interface Config {
 
 Source: [`packages/subagent/subagent-fork/src/index.ts:25`](../packages/subagent/subagent-fork/src/index.ts)
 
+## `@deepseek-ai/dsh-subagent-sdk`
+
+Requires: `subagents`
+
+```ts config-catalog
+/** Config: how to spawn and drive the child SDK runtime process. */
+export interface Config {
+  /** Provider name on `ctx.subagents` (default `sdk`). */
+  providerName: string
+  /** The executable to spawn for each run (the child runtime bin or packaged exe). */
+  command: string
+  /** Arguments passed to {@link command} (typically the child's `cordis.yml` path). */
+  args: string[]
+  /**
+   * Working directory override for the child process and its SDK session
+   * workspace. Must be non-empty; a relative path resolves against the
+   * harness launch directory at load, and the result must be an existing
+   * directory. When omitted, each child inherits its delegating parent
+   * session's cwd — and starting one from a parent session that has no cwd
+   * fails.
+   */
+  cwd?: string
+  /** Provider route the child runtime initializes with (default `deepseek`). */
+  provider: string
+  /** Model the child runtime initializes with (default `deepseek-v4-flash`). */
+  model: string
+  /**
+   * Extra environment variables for the child process — e.g. the child
+   * runtime's own `DEEPSEEK_API_KEY`, or `DSH_CORDIS_CONFIG` naming its
+   * config. Forwarded on top of a credential-scrubbed copy of the parent
+   * env, so an explicit key here reaches the child while ambient secrets do
+   * not leak implicitly.
+   */
+  env: Record<string, string>
+  /** Bound (ms) on the protocol `shutdown` exchange during dispose. */
+  shutdownTimeoutMs?: number
+  /**
+   * Grace period (ms) for the child's EOF-driven quiesce on dispose — its
+   * window to flush persistence and tear down its own nested subprocesses
+   * before the parent escalates to a signal.
+   */
+  disposeEofGraceMs?: number
+  /** Termination confirmation window (ms), including forced exit on every platform. */
+  disposeGraceMs?: number
+}
+```
+
+Source: [`packages/subagent/subagent-sdk/src/index.ts:29`](../packages/subagent/subagent-sdk/src/index.ts)
+
 ## `@deepseek-ai/dsh-subagent-spawn`
 
 Requires: `subagents`
@@ -2113,6 +2162,8 @@ Imported as libraries by other packages; a `cordis.yml` cannot load them.
 - `@deepseek-ai/dsh-retention` ([`packages/util/retention/src/index.ts`](../packages/util/retention/src/index.ts))
 - `@deepseek-ai/dsh-scope` ([`packages/core/scope/src/index.ts`](../packages/core/scope/src/index.ts))
 - `@deepseek-ai/dsh-scripts` ([`packages/sdk/scripts/src/index.ts`](../packages/sdk/scripts/src/index.ts))
+- `@deepseek-ai/dsh-sdk-client` ([`packages/sdk/sdk-client/src/index.ts`](../packages/sdk/sdk-client/src/index.ts))
+- `@deepseek-ai/dsh-sdk-protocol` ([`packages/sdk/sdk-protocol/src/index.ts`](../packages/sdk/sdk-protocol/src/index.ts))
 - `@deepseek-ai/dsh-session-title-llm` ([`packages/session-title/session-title-llm/src/index.ts`](../packages/session-title/session-title-llm/src/index.ts))
 - `@deepseek-ai/dsh-subagent-inprocess` ([`packages/subagent/subagent-inprocess/src/index.ts`](../packages/subagent/subagent-inprocess/src/index.ts))
 - `@deepseek-ai/dsh-subagent-subprocess` ([`packages/subagent/subagent-subprocess/src/index.ts`](../packages/subagent/subagent-subprocess/src/index.ts))