multi_agent_chat/middleware: refresh module layout docs

surfsense_backend/app/agents/multi_agent_chat/middleware/main_agent/checkpointed_subagent_middleware/__init__.py

@@ -4,21 +4,27 @@ Replaces upstream ``SubAgentMiddleware`` to:
 
 - share the parent's checkpointer with each subagent,
 - forward ``runtime.config`` (thread_id, recursion_limit, …) into nested invokes,
+- isolate each parallel ``task`` call in its own checkpoint slot via
+  per-call ``thread_id`` namespacing,
 - bridge ``Command(resume=...)`` from the parent into the subagent via the
-  ``config["configurable"]["surfsense_resume_value"]`` side-channel,
+  ``config["configurable"]["surfsense_resume_value"]`` side-channel, keyed by
+  ``tool_call_id`` so parallel siblings never race on a shared scalar,
 - target the resume at the captured interrupt id so a follow-up
   ``HumanInTheLoopMiddleware.after_model`` does not consume the same payload,
-- re-raise any new subagent interrupt at the parent so the SSE stream surfaces it.
+- stamp each subagent's pending interrupt with the parent's ``tool_call_id``
+  so ``stream_resume_chat`` can route a flat ``decisions`` list back to the
+  right paused subagent.
 
 Module layout
 -------------
 
-- ``constants``   — shared keys / limits.
-- ``config``      — RunnableConfig + side-channel resume read.
-- ``resume``      — pending-interrupt detection, fan-out, ``Command(resume=...)`` builder.
-- ``propagation`` — re-raise pending subagent interrupts at the parent.
-- ``task_tool``   — the ``task`` tool factory (sync + async).
-- ``middleware``  — :class:`SurfSenseCheckpointedSubAgentMiddleware` itself.
+- ``constants``     — shared keys / limits.
+- ``config``        — RunnableConfig + side-channel resume read + per-call ``thread_id``.
+- ``resume``        — pending-interrupt detection, fan-out, ``Command(resume=...)`` builder.
+- ``propagation``   — ``wrap_with_tool_call_id`` helper for stamping interrupt values.
+- ``resume_routing``— slice a flat decisions list to per-``tool_call_id`` payloads.
+- ``task_tool``     — the ``task`` tool factory (sync + async), and the catch-and-stamp chokepoint.
+- ``middleware``    — :class:`SurfSenseCheckpointedSubAgentMiddleware` itself.
 """
 
 from .middleware import SurfSenseCheckpointedSubAgentMiddleware