refactor: add typed mcp source connection seam

tests/wf_sources_mcp/test_sdk_protocols.py

@@ -3,16 +3,17 @@ from __future__ import annotations
 from dataclasses import is_dataclass
 from typing import cast
 
-from wf_mcp.broker.models import ConnectionConfig
 from wf_sources_mcp.auth import AuthRecord
 from wf_sources_mcp.catalog import DiscoveredTool
+from wf_sources_mcp.connections import McpSourceConnection
 from wf_sources_mcp.sdk import BackendAdapter, ToolCallResult, ToolExecutor
+from wf_sources_mcp.transports import StdioSourceTransport
 
 
 class EchoAdapter:
     async def list_tools(
         self,
-        connection: ConnectionConfig,
+        connection: McpSourceConnection,
         auth: AuthRecord | None,
     ) -> list[DiscoveredTool]:
         return [
@@ -27,7 +28,7 @@ class EchoAdapter:
 
     async def call_tool(
         self,
-        connection: ConnectionConfig,
+        connection: McpSourceConnection,
         auth: AuthRecord | None,
         tool_name: str,
         payload: dict[str, object],
@@ -46,7 +47,12 @@ def test_tool_call_result_is_slots_dataclass_with_empty_defaults() -> None:
 async def test_backend_adapter_protocol_can_describe_tool_listing() -> None:
     adapter = cast(BackendAdapter, EchoAdapter())
     tools = await adapter.list_tools(
-        ConnectionConfig(id="demo.default", server="demo", account="default"),
+        McpSourceConnection(
+            id="demo.default",
+            provider="demo",
+            account="default",
+            transport=StdioSourceTransport(command="echo"),
+        ),
         None,
     )
 
@@ -56,7 +62,12 @@ async def test_backend_adapter_protocol_can_describe_tool_listing() -> None:
 async def test_tool_executor_protocol_can_describe_tool_calls() -> None:
     executor = cast(ToolExecutor, EchoAdapter())
     result = await executor.call_tool(
-        ConnectionConfig(id="demo.default", server="demo", account="default"),
+        McpSourceConnection(
+            id="demo.default",
+            provider="demo",
+            account="default",
+            transport=StdioSourceTransport(command="echo"),
+        ),
         None,
         "echo",
         {"message": "hello"},