fix(python): mount session checkpoint policy

python/sdk-runtime/README.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write
-README.md: cdf38d4474a0e0148a4804e14c12971c76b38e27
-README.zh.md: 99d57c6f900371a46b94c5ea80b2a1665fd5e8d1
+README.md: f2ccd8939e497d10359aafe8b1bd8b364875ed98
+README.zh.md: 30bdf46fee03c38a1f4b6e8b2b39d87e8174a3e0

python/sdk-runtime/README.md

@@ -26,4 +26,4 @@ Each wheel contains exactly one executable. The fixed tags are `py3-none-manylin
 
 ## Zero-config design
 
-The runtime binary always demands an explicit config (`$DSH_CORDIS_CONFIG`, or a config path as an argv positional argument) and exits loudly without one — that hard semantic is part of the runtime's design and this package does not soften it. The bin (`dsh-jsonrpc-agent`) boots only the plugins the config lists; the serving surface (the stdio JSON-RPC server) is itself one of its entries (`@deepseek-ai/dsh-jsonrpc`), and without it the booted agent has no channel to the outside. This package checks in `runtime/cordis.yml` with the JSON-RPC serving entry, agent core, a preloaded DeepSeek adapter, JSONL persistence, local bash, and a local filesystem provider for bounded workspace-instruction loading. The adapter reads `DEEPSEEK_API_KEY` and `DEEPSEEK_BASE_URL`, while persistence, bash, and the filesystem provider use `DSH_SESSION_ROOT` and `DSH_CWD` with manual-run fallbacks. When the caller uses no explicit config channel, the `deepseek_harness` client injects that file's path via `DSH_CORDIS_CONFIG` (injection conditions: [sdk README](../sdk/README.md)). Zero-config is thus an explicit, visible parameter pass in the wrapper, not a hidden fallback in the runtime.
+The runtime binary always demands an explicit config (`$DSH_CORDIS_CONFIG`, or a config path as an argv positional argument) and exits loudly without one — that hard semantic is part of the runtime's design and this package does not soften it. The bin (`dsh-jsonrpc-agent`) boots only the plugins the config lists; the serving surface (the stdio JSON-RPC server) is itself one of its entries (`@deepseek-ai/dsh-jsonrpc`), and without it the booted agent has no channel to the outside. This package checks in `runtime/cordis.yml` with the JSON-RPC serving entry, agent core, a preloaded DeepSeek adapter, JSONL persistence, the explicitly composed semantic checkpoint policy, local bash, and a local filesystem provider for bounded workspace-instruction loading. The persistence backend owns durable storage while the separate policy selects request-, tool-dispatch-, and completed-step checkpoints. The adapter reads `DEEPSEEK_API_KEY` and `DEEPSEEK_BASE_URL`, while persistence, bash, and the filesystem provider use `DSH_SESSION_ROOT` and `DSH_CWD` with manual-run fallbacks. When the caller uses no explicit config channel, the `deepseek_harness` client injects that file's path via `DSH_CORDIS_CONFIG` (injection conditions: [sdk README](../sdk/README.md)). Zero-config is thus an explicit, visible parameter pass in the wrapper, not a hidden fallback in the runtime.

python/sdk-runtime/README.zh.md

@@ -26,4 +26,4 @@ exe 缺失时抛出 `FileNotFoundError`，并写明两种获取途径：在 deep
 
 ## 零配置设计
 
-运行时二进制始终要求显式配置（`$DSH_CORDIS_CONFIG`，或作为 argv 位置参数的配置路径），缺了就报错退出——这一硬语义是运行时设计的一部分，本包不软化它。`bin`（`dsh-jsonrpc-agent`）只启动配置里列出的插件；对外服务接口（stdio JSON-RPC 服务器）也是其中一个条目（`@deepseek-ai/dsh-jsonrpc`），缺了它，启动出的 agent 就没有对外通道。本包检入的 `runtime/cordis.yml` 包含 JSON-RPC 服务条目、`agent-core`、预载的 DeepSeek 适配器、JSONL 持久化、本地 bash，以及用于有界加载工作区指令的本地文件系统 provider。DeepSeek 适配器读取 `DEEPSEEK_API_KEY` 与 `DEEPSEEK_BASE_URL`，持久化、bash 和文件系统 provider 则使用 `DSH_SESSION_ROOT` 和 `DSH_CWD`，并为手动运行提供回退值。调用方未使用任何显式配置通道时，`deepseek_harness` 客户端把该文件路径注入 `DSH_CORDIS_CONFIG`（注入条件见 [sdk README](../sdk/README.md)）。因此，零配置是包装层中一次显式、可见的参数传递，而不是运行时中的隐藏回退。
+运行时二进制始终要求显式配置（`$DSH_CORDIS_CONFIG`，或作为 argv 位置参数的配置路径），缺了就报错退出——这一硬语义是运行时设计的一部分，本包不软化它。`bin`（`dsh-jsonrpc-agent`）只启动配置里列出的插件；对外服务接口（stdio JSON-RPC 服务器）也是其中一个条目（`@deepseek-ai/dsh-jsonrpc`），缺了它，启动出的 agent 就没有对外通道。本包检入的 `runtime/cordis.yml` 包含 JSON-RPC 服务条目、`agent-core`、预载的 DeepSeek 适配器、JSONL 持久化、显式组合的语义检查点策略、本地 bash，以及用于有界加载工作区指令的本地文件系统 provider。持久化后端负责持久存储，独立的策略则选择请求、工具分发和已完成步骤的检查点。DeepSeek 适配器读取 `DEEPSEEK_API_KEY` 与 `DEEPSEEK_BASE_URL`，持久化、bash 和文件系统 provider 则使用 `DSH_SESSION_ROOT` 和 `DSH_CWD`，并为手动运行提供回退值。调用方未使用任何显式配置通道时，`deepseek_harness` 客户端把该文件路径注入 `DSH_CORDIS_CONFIG`（注入条件见 [sdk README](../sdk/README.md)）。因此，零配置是包装层中一次显式、可见的参数传递，而不是运行时中的隐藏回退。

python/sdk-runtime/package.json

@@ -47,6 +47,7 @@
     "@deepseek-ai/dsh-sandbox-policy": "workspace:^",
     "@deepseek-ai/dsh-scope": "workspace:^",
     "@deepseek-ai/dsh-session": "workspace:^",
+    "@deepseek-ai/dsh-session-checkpoint-policy": "workspace:^",
     "@deepseek-ai/dsh-session-persistence": "workspace:^",
     "@deepseek-ai/dsh-session-persistence-jsonl": "workspace:^",
     "@deepseek-ai/dsh-session-persistence-sqlite": "workspace:^",

python/sdk-runtime/src/deepseek_harness_runtime/runtime/cordis.yml

@@ -27,6 +27,11 @@
   config:
     root: !!js process.env.DSH_SESSION_ROOT ?? './.sessions'
 
+# Persistence owns durable storage; this separate policy explicitly selects
+# the request, tool-dispatch, and completed-step durability checkpoints.
+- id: session-checkpoints
+  name: '@deepseek-ai/dsh-session-checkpoint-policy'
+
 # Local bash executor; $DSH_CWD wins over the process cwd.
 - id: bash
   name: '@deepseek-ai/dsh-bash-local'