feat : 推理层增加 vLLM 风格工具调用解析

- 新增 BaseToolParser 抽象基类，定义 feed/parse_complete 流式接口
- 新增 SimpleJsonToolParser，解析 {"name":"...","arguments":{...}} 格式
- 新增 ToolParserFactory，基于 BaseFactory 实现可插拔注册
- 集成 parser 到 OpenAIResponseBuilder，支持流式/非流式工具调用
- 扩展 ChatMessage 和 ChatCompletionRequest，增加 tools/tool_choice 字段
- 重构 format_chunk 接口，传入累积文本支持全量重新解析
- 新增 74 个单元测试，覆盖扫描/查找/流式解析/完整解析/工厂

tests/inference/test_protocol.py

@@ -121,8 +121,8 @@ class TestOpenAIResponseBuilder:
         assert p["choices"][0]["finish_reason"] is None
 
     def test_format_chunk(self, builder):
-        event = builder.format_chunk("hello")
-        payload = json.loads(event.split("data: ", 1)[1])
+        events = builder.format_chunk("hello", "hello")
+        payload = json.loads(events[0].split("data: ", 1)[1])
         assert payload["choices"][0]["delta"]["content"] == "hello"
         assert payload["choices"][0]["finish_reason"] is None
 
@@ -192,8 +192,8 @@ class TestAnthropicResponseBuilder:
         assert payloads[1]["type"] == "content_block_start"
 
     def test_format_chunk(self, builder):
-        event = builder.format_chunk("tok")
-        payload = json.loads(event.split("data: ", 1)[1])
+        events = builder.format_chunk("tok", "tok")
+        payload = json.loads(events[0].split("data: ", 1)[1])
         assert payload["type"] == "content_block_delta"
         assert payload["delta"]["text"] == "tok"