refactor(agent): restructure visibility masks, task queues, and memory service

Visibility mask refactoring:
- Replace dead UI_REALTIME bit with CONTEXT_ASSEMBLY (bit 1)
- Remove visibility_consumer_bit from SystemAgentLLMConfig and system_agents.yaml
- Simplify _resolve_user_message_visibility_mask: chat->UI_HISTORY|CONTEXT_ASSEMBLY, automation->0
- Simplify _resolve_stage_visibility_mask: memory->UI_HISTORY, router/worker->UI_HISTORY|CONTEXT_ASSEMBLY
- Remove stage_visibility_bit_map from store.py

Task queue renaming:
- Replace default_broker/bulk_broker/critical_broker with worker_agent_broker/worker_automation_broker
- Queue names: 'default'/'bulk'/'critical' -> 'agent'/'automation'
- Rename run_command_task -> run_command_task_agent/run_command_task_automation
- AgentService derives queue from runtime_mode: chat->agent, automation->automation

Architecture cleanup:
- Move context_service.py from runtime/ to agentscope/services/
- Add MemoryService in v1/memory/ following repository/service pattern
- Move consumer_registry.py and pipeline_spec.py from schemas/agent to agentscope/schemas/
- Delete dead code: registry_builder.py, VisibilityBitRef
- Delete superseded plan docs

backend/src/schemas/agent/__init__.py

@@ -1,17 +1,10 @@
-from schemas.agent.consumer_registry import AgentConsumerBinding, ConsumerRegistry
 from schemas.agent.forwarded_props import (
     ClientTimeContext,
     ForwardedPropsPayload,
-    parse_forwarded_props_agent_type,
     parse_forwarded_props_client_time,
+    parse_forwarded_props_runtime_mode,
 )
-from schemas.agent.pipeline_spec import (
-    ContextPolicy,
-    ContextWindowMode,
-    ExecutorKind,
-    PipelineSpec,
-    StageSpec,
-)
+from schemas.agent.forwarded_props import RuntimeMode
 from schemas.agent.runtime_models import (
     AgentOutput,
     ConstraintItem,
@@ -45,28 +38,22 @@ from schemas.agent.ui_hints import (
 __all__ = [
     "AgentType",
     "AgentOutput",
-    "AgentConsumerBinding",
     "ConstraintItem",
-    "ConsumerRegistry",
-    "ContextPolicy",
-    "ContextWindowMode",
     "ExecutionMode",
-    "ExecutorKind",
     "ForwardedPropsPayload",
     "KeyEntity",
     "NormalizedTaskInput",
-    "PipelineSpec",
     "ResultTyping",
     "ClientTimeContext",
     "ResultType",
     "RouterAgentOutput",
     "RouterUiDecision",
     "RunStatus",
+    "RuntimeMode",
     "TaskType",
     "TaskTyping",
     "SystemAgentLLMConfig",
     "SystemVisibilityBit",
-    "StageSpec",
     "ToolAgentOutput",
     "ToolStatus",
     "UiMode",
@@ -79,7 +66,7 @@ __all__ = [
     "WorkerAgentOutputLite",
     "WorkerAgentOutputRich",
     "bit_mask",
-    "parse_forwarded_props_agent_type",
     "parse_forwarded_props_client_time",
+    "parse_forwarded_props_runtime_mode",
     "resolve_worker_output_model",
 ]