fix(python): mount session checkpoint policy

python/sdk/tests/test_bundled_runtime.py

@@ -28,6 +28,8 @@ _CORDIS_YML = """\
   name: '@deepseek-ai/dsh-session-persistence-jsonl'
   config:
     root: './sessions'
+- id: session-checkpoints
+  name: '@deepseek-ai/dsh-session-checkpoint-policy'
 - id: bash
   name: '@deepseek-ai/dsh-bash-local'
   config:

python/sdk/tests/test_runtime_resolution.py

@@ -15,7 +15,10 @@ from deepseek_harness_runtime import (
 def test_default_config_is_shipped_with_the_package() -> None:
     path = bundled_default_config_path()
     assert path == bundled_package_dir() / "runtime" / "cordis.yml"
-    assert "@deepseek-ai/dsh-agent-spine-demo" in path.read_text()
+    config = path.read_text()
+    assert "@deepseek-ai/dsh-agent-spine-demo" in config
+    assert "@deepseek-ai/dsh-session-persistence-jsonl" in config
+    assert "@deepseek-ai/dsh-session-checkpoint-policy" in config
 
 
 def test_unknown_explicit_mode_fails_loud() -> None: