docs(reference): align A2A facade API with implementation

Fixes docs/reference/a2a.md Local Facade section. Issues #6620 and #6624.

Fixes #6620
Fixes #6624

Automatically merged by PR Merge Pool Supervisor [AUTO-PRMRG-SUP]

---
**Automated by CleverAgents Bot**
Supervisor: PR Merge | Agent: pr-merge-pool-supervisor
Co-authored-by: CleverThis <hal9000@cleverthis.com>
Co-committed-by: CleverThis <hal9000@cleverthis.com>

docs/reference/a2a.md

@@ -259,6 +259,7 @@ resuming the task.
 
 ```python
 from cleveragents.a2a import A2aLocalFacade
+from cleveragents.a2a.models import A2aRequest
 
 facade = A2aLocalFacade(services={
     "session_service": my_session_service,
@@ -267,8 +268,11 @@ facade = A2aLocalFacade(services={
     "resource_registry_service": my_resource_registry_service,
 })
 
-# Extension methods are dispatched to in-process services
-result = await facade.dispatch("_cleveragents/plan/status", {"plan_id": "01J..."})
+# Extension methods are dispatched to in-process services (synchronous)
+response = facade.dispatch(A2aRequest(
+    method="_cleveragents/plan/status",
+    params={"plan_id": "01J..."}
+))
 ```
 
 ### Constructor
@@ -279,11 +283,11 @@ result = await facade.dispatch("_cleveragents/plan/status", {"plan_id": "01J..."
 
 ### Methods
 
-| Method                     | Returns           | Description                          |
-|----------------------------|-------------------|--------------------------------------|
-| `dispatch(method, params)` | `dict`            | Route extension method to handler    |
-| `register_service`         | `None`            | Register a named service             |
-| `list_methods`             | `list[str]`       | All supported extension method names |
+| Method                          | Returns           | Description                          |
+|---------------------------------|-------------------|--------------------------------------|
+| `dispatch(request: A2aRequest)` | `A2aResponse`     | Route extension method to handler    |
+| `register_service`              | `None`            | Register a named service             |
+| `list_operations()`             | `list[str]`       | All supported extension method names |
 
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