feat(memory): 实现灵活搜索模式并重构记忆格式化系统

- 新增灵活匹配模式(flexible_mode)，支持2/4项匹配即可的记忆检索策略
- 删除冗余的memory_formatter模块，简化记忆系统架构
- 增强枚举值解析机制，支持字符串、整数和枚举实例的自动转换
- 优化元数据索引搜索逻辑，分离严格模式和灵活模式的实现路径
- 改进向量存储的搜索回退机制，当元数据筛选无结果时自动回退到全量搜索
- 统一记忆类型映射管理，避免重复的格式化函数定义

这些变更提升了记忆检索的准确性和灵活性，同时简化了代码结构，提高了系统可维护性。

src/chat/replyer/default_generator.py

@@ -18,6 +18,7 @@ from src.individuality.individuality import get_individuality
 from src.llm_models.utils_model import LLMRequest
 from src.chat.message_receive.message import UserInfo, Seg, MessageRecv, MessageSending
 from src.chat.message_receive.chat_stream import ChatStream
+from src.chat.utils.memory_mappings import get_memory_type_chinese_label
 from src.chat.message_receive.uni_message_sender import HeartFCSender
 from src.chat.utils.timer_calculator import Timer
 from src.chat.utils.utils import get_chat_type_and_target_info
@@ -621,20 +622,6 @@ class DefaultReplyer:
                 running_memories = []
                 instant_memory = ""
 
-        def _format_confidence_label(value: Optional[float]) -> str:
-            if value is None:
-                return "未知"
-            mapping = {4: "已验证", 3: "高", 2: "中等", 1: "较低"}
-            rounded = int(value)
-            return mapping.get(rounded, f"{value:.2f}")
-
-        def _format_importance_label(value: Optional[float]) -> str:
-            if value is None:
-                return "未知"
-            mapping = {4: "关键", 3: "高", 2: "一般", 1: "较低"}
-            rounded = int(value)
-            return mapping.get(rounded, f"{value:.2f}")
-
         # 构建记忆字符串，使用方括号格式
         memory_str = ""
         has_any_memory = False
@@ -662,16 +649,8 @@ class DefaultReplyer:
                     logger.debug(f"[记忆构建] 空记忆详情: {running_memory}")
                     continue
 
-                # 映射记忆类型到中文标签
-                type_mapping = {
-                    "personal_fact": "个人事实",
-                    "preference": "偏好",
-                    "event": "事件",
-                    "opinion": "观点",
-                    "relationship": "个人事实",
-                    "unknown": "未知"
-                }
-                chinese_type = type_mapping.get(memory_type, "未知")
+                # 使用全局记忆类型映射表
+                chinese_type = get_memory_type_chinese_label(memory_type)
 
                 # 提取纯净内容（如果包含旧格式的元数据）
                 clean_content = content