feat:完善长期记忆控制台导入链路与联调测试

summary:\n- 扩展长期记忆控制台导入、调优与删除相关 UI/接口，补充中文化展示与任务细粒度状态管理\n- 强化 memory API 与后端路由能力，补齐导入任务、图谱检索、配置与运行态相关字段\n- 新增与增强前后端测试，覆盖导入多文件类型、检索、调优、删除及图谱查询关键路径

description:\n- dashboard: 重构 knowledge-base 页面与 memory-api，统一任务队列、分块分页、来源删除恢复、调优闭环交互\n- backend: 扩展 webui memory 路由与 A_Memorix 内核检索逻辑，完善服务侧能力与配置 schema\n- tests: 增加 webui 集成测试和 kernel 单测，提升导入/检索/调优/删除全流程回归保障

src/webui/routers/memory.py

@@ -168,6 +168,10 @@ async def _graph_get(limit: int) -> dict:
     return await memory_service.graph_admin(action="get_graph", limit=limit)
 
 
+async def _graph_search(query: str, limit: int) -> dict:
+    return await memory_service.graph_admin(action="search", query=query, limit=limit)
+
+
 async def _graph_get_node_detail(
     node_id: str,
     *,
@@ -390,9 +394,20 @@ async def _memory_config_get() -> dict:
 
 
 async def _memory_config_get_raw() -> dict:
+    raw_payload_getter = getattr(a_memorix_host_service, "get_raw_config_with_meta", None)
+    if callable(raw_payload_getter):
+        raw_payload = raw_payload_getter()
+    else:
+        raw_payload = {
+            "config": a_memorix_host_service.get_raw_config(),
+            "exists": bool(a_memorix_host_service.get_config_path().exists()),
+            "using_default": False,
+        }
     return {
         "success": True,
-        "config": a_memorix_host_service.get_raw_config(),
+        "config": str(raw_payload.get("config", "") or ""),
+        "exists": bool(raw_payload.get("exists", False)),
+        "using_default": bool(raw_payload.get("using_default", False)),
         "path": str(a_memorix_host_service.get_config_path()),
     }
 
@@ -649,6 +664,14 @@ async def get_memory_graph(limit: int = Query(200, ge=1, le=5000)):
     return await _graph_get(limit)
 
 
+@router.get("/graph/search")
+async def search_memory_graph(
+    query: str = Query(..., min_length=1),
+    limit: int = Query(50, ge=1, le=200),
+):
+    return await _graph_search(query, limit)
+
+
 @router.get("/graph/node-detail")
 async def get_memory_graph_node_detail(
     node_id: str = Query(..., min_length=1),