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- Delete superseded plan docs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/tests/unit/v1/agent/test_service.py

@@ -159,7 +159,7 @@ def _user() -> CurrentUser:
     )
 
 
-def _build_run_input(*, urls: list[str], agent_type: str = "worker") -> RunAgentInput:
+def _build_run_input(*, urls: list[str], runtime_mode: str = "chat") -> RunAgentInput:
     content: list[dict[str, str]] = [{"type": "text", "text": "hello"}]
     for url in urls:
         content.append({"type": "binary", "mimeType": "image/png", "url": url})
@@ -177,7 +177,7 @@ def _build_run_input(*, urls: list[str], agent_type: str = "worker") -> RunAgent
             ],
             "tools": [],
             "context": [],
-            "forwardedProps": {"agent_type": agent_type},
+            "forwardedProps": {"runtime_mode": runtime_mode},
         }
     )
 
@@ -275,7 +275,7 @@ async def test_enqueue_run_rejects_unknown_agent_type(monkeypatch) -> None:
         urls=[
             f"{base_url}/storage/v1/object/sign/agent-test-bucket/{safe_path}?token=1"
         ],
-        agent_type="planner",
+        runtime_mode="planner",
     )
 
     with pytest.raises(HTTPException) as exc_info:
@@ -285,7 +285,7 @@ async def test_enqueue_run_rejects_unknown_agent_type(monkeypatch) -> None:
 
 
 @pytest.mark.asyncio
-async def test_enqueue_run_rejects_memory_mode_for_api(monkeypatch) -> None:
+async def test_enqueue_run_rejects_invalid_runtime_mode(monkeypatch) -> None:
     monkeypatch.setattr(
         agent_service_module.config.storage, "bucket", "agent-test-bucket"
     )
@@ -296,24 +296,12 @@ async def test_enqueue_run_rejects_memory_mode_for_api(monkeypatch) -> None:
         stream=_FakeStream(),
         attachment_storage=_FakeAttachmentStorage(),
     )
-    base_url = str(config.supabase.url).rstrip("/")
-    safe_path = quote(
-        "agent-inputs/00000000-0000-0000-0000-000000000001/"
-        "00000000-0000-0000-0000-000000000001/uploads/a.png"
-    )
-    run_input = _build_run_input(
-        urls=[
-            f"{base_url}/storage/v1/object/sign/agent-test-bucket/{safe_path}?token=1"
-        ],
-        agent_type="memory",
-    )
+    run_input = _build_run_input(urls=[], runtime_mode="planner")
 
     with pytest.raises(HTTPException) as exc_info:
         await service.enqueue_run(run_input=run_input, current_user=_user())
 
     assert exc_info.value.status_code == 422
-    assert exc_info.value.detail == "memory mode is automation-only"
-    assert repository.created_session_calls == 0
     assert repository.persisted_user_messages == []