refactor(agent-runner): remove protocol_version from various components and update related documentation

src/langbot/pkg/agent/runner/context_builder.py

@@ -124,7 +124,6 @@ class AgentRuntimeContext(typing.TypedDict):
     """Agent runtime context."""
 
     langbot_version: str | None
-    protocol_version: str
     trace_id: str | None
     deadline_at: float | None
     metadata: dict[str, typing.Any]
@@ -272,7 +271,6 @@ class AgentRunContextBuilder:
         # Build runtime context
         runtime: AgentRuntimeContext = {
             'langbot_version': self.ap.ver_mgr.get_current_version(),
-            'protocol_version': descriptor.protocol_version,
             'trace_id': run_id,
             'deadline_at': self._build_deadline_from_binding(binding),
             'metadata': {
@@ -424,6 +422,5 @@ class AgentRunContextBuilder:
                 'artifact_read': artifact_read_enabled,
                 'state': state_enabled,
                 'storage': True,
-                'prompt_get': False,
             },
         }