♻️ refactor!: 重构LLM服务架构并统一Pydantic兼容性处理 (#2002)

* ♻️ refactor(pydantic): 提取 Pydantic 兼容函数到独立模块

* ♻️ refactor!(llm): 重构LLM服务，引入现代化工具和执行器架构

🏗️ **架构变更**
- 引入ToolProvider/ToolExecutable协议，取代ToolRegistry
- 新增LLMToolExecutor，分离工具调用逻辑
- 新增BaseMemory抽象，解耦会话状态管理

🔄 **API重构**
- 移除：analyze, analyze_multimodal, pipeline_chat
- 新增：generate_structured, run_with_tools
- 重构：chat, search, code变为无状态调用

🛠️ **工具系统**
- 新增@function_tool装饰器
- 统一工具定义到ToolExecutable协议
- 移除MCP工具系统和mcp_tools.json

---------

Co-authored-by: webjoin111 <455457521@qq.com>

zhenxun/services/llm/__init__.py

@@ -5,15 +5,13 @@ LLM 服务模块 - 公共 API 入口
 """
 
 from .api import (
-    analyze,
-    analyze_multimodal,
     chat,
     code,
     embed,
     generate,
-    pipeline_chat,
+    generate_structured,
+    run_with_tools,
     search,
-    search_multimodal,
 )
 from .config import (
     CommonOverrides,
@@ -34,7 +32,7 @@ from .manager import (
     set_global_default_model_name,
 )
 from .session import AI, AIConfig
-from .tools import tool_registry
+from .tools import function_tool, tool_provider_manager
 from .types import (
     EmbeddingTaskType,
     LLMContentPart,
@@ -42,8 +40,6 @@ from .types import (
     LLMException,
     LLMMessage,
     LLMResponse,
-    LLMTool,
-    MCPCompatible,
     ModelDetail,
     ModelInfo,
     ModelProvider,
@@ -66,8 +62,6 @@ __all__ = [
     "LLMGenerationConfig",
     "LLMMessage",
     "LLMResponse",
-    "LLMTool",
-    "MCPCompatible",
     "ModelDetail",
     "ModelInfo",
     "ModelName",
@@ -77,14 +71,14 @@ __all__ = [
     "ToolCategory",
     "ToolMetadata",
     "UsageInfo",
-    "analyze",
-    "analyze_multimodal",
     "chat",
     "clear_model_cache",
     "code",
     "create_multimodal_message",
     "embed",
+    "function_tool",
     "generate",
+    "generate_structured",
     "get_cache_stats",
     "get_global_default_model_name",
     "get_model_instance",
@@ -92,11 +86,10 @@ __all__ = [
     "list_embedding_models",
     "list_model_identifiers",
     "message_to_unimessage",
-    "pipeline_chat",
     "register_llm_configs",
+    "run_with_tools",
     "search",
-    "search_multimodal",
     "set_global_default_model_name",
-    "tool_registry",
+    "tool_provider_manager",
     "unimsg_to_llm_parts",
 ]