refactor: route mcp runtime operations through client facade

docs/current_roadmap.md

@@ -242,6 +242,10 @@ implementation state.
       `wf_sources_mcp.client`. The one-shot SDK adapter delegates MCP operation
       calls and conversion through the facade; persistent runtime remains
       tool-call-only until a separate owner-task routing slice.
+    - Completed: persistent MCP runtime owner now uses a generic explicit
+      operation queue with request metadata and `McpSourceClient` execution.
+      Public runtime remains tool-call-only; `operation` strings are diagnostics
+      labels, not dispatch.
   - Auth/source secrets boundary: keep registry desired state separate from
     upstream credentials, and surface missing auth as validation diagnostics.
     The contract is now specified in

docs/superpowers/specs/2026-06-03-long-lived-workflow-api-boundary.md

@@ -111,7 +111,10 @@ First slices should move leaf modules only and leave `wf_mcp` re-export shims:
    `wf_sources_mcp.client`. `McpSdkAdapter` now delegates operation handling to
    this facade. Persistent runtime still exposes only `call_tool`; expanding it
    requires a separate owner-task request routing slice.
-10. Upstream transport/discovery/session services.
+10. Complete: persistent MCP runtime owner now routes explicit callables through
+    a generic operation queue with request metadata. The runtime still exposes
+    only `call_tool`; non-tool methods require a separate public-surface slice.
+11. Upstream transport/discovery/session services.
 
 Each slice should add import-direction tests so the new source-provider package
 does not depend on `wf_mcp.workflow_surface`, `wf_mcp.admin_surface`,