feat(agent-runner): expose effective prompt pull api

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

@@ -422,6 +422,7 @@ class AgentRunContextBuilder:
                 'reason': 'current_event_only',
             },
             'available_apis': {
+                'prompt_get': False,
                 'history_page': history_page_enabled,
                 'history_search': history_search_enabled,
                 'event_get': event_get_enabled,

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

@@ -96,6 +96,8 @@ class AgentRunOrchestrator:
                     context.get('state', {}),
                 )
             session_query_id = adapter_context.get('query_id')
+            if query is not None or session_query_id is not None:
+                context['context']['available_apis']['prompt_get'] = True
             if 'params' in adapter_context:
                 context['adapter']['extra']['params'] = adapter_context['params']