feat: stateless certified shared worker

Implements stateless singleton component model for certified shared Workers, integrating with SDK 0.7.0.

tests/integration/persistence/test_migration_branch_convergence.py

@@ -370,7 +370,7 @@ def _legacy_shared_certification(**overrides):
 
 
 @pytest.mark.asyncio
-async def test_certification_artifact_digest_backfill_is_safe_and_enables_shared_placement(convergence_engine):
+async def test_certification_artifact_digest_backfill_is_safe_and_keeps_legacy_dedicated(convergence_engine):
     engine = convergence_engine
     async with engine.begin() as conn:
         await conn.run_sync(Base.metadata.create_all)
@@ -461,7 +461,7 @@ async def test_certification_artifact_digest_backfill_is_safe_and_enables_shared
                 artifact_digest=eligible_digest,
                 install_info=eligible_info,
             )
-            is PluginExecutionMode.SHARED_CERTIFIED
+            is PluginExecutionMode.DEDICATED
         )
 
     for name, (original_certification, artifact_digest) in rows.items():

tests/integration/plugin/test_certified_plugin_admission.py

@@ -249,7 +249,10 @@ def _connector(deployment: str, trusted_public_keys: dict[str, str]):
 def _archive(kind: str) -> tuple[bytes, dict[str, str]]:
     manifest = {
         'metadata': {'author': 'certified', 'name': 'example', 'version': '1.0.0'},
-        'execution': {'sharedRuntime': 'shared-runtime-v1'},
+        'execution': {
+            'sharedRuntime': 'shared-runtime-v1',
+            'componentModel': 'stateless-v1',
+        },
     }
     if kind == 'legacy':
         manifest.pop('execution')