feat: 推理引擎数据模型与异常层（types/exceptions）及 httpx/jinja2 依赖

tests/test_inference_errors.py

@@ -0,0 +1,21 @@
+import pytest
+
+from genesis.inference.exceptions import (
+    LLMError,
+    LLMNetworkError,
+    LLMNotConfiguredError,
+    LLMResponseError,
+    LLMTimeoutError,
+)
+
+
+def test_error_hierarchy():
+    assert issubclass(LLMNetworkError, LLMError)
+    assert issubclass(LLMTimeoutError, LLMError)
+    assert issubclass(LLMNotConfiguredError, LLMError)
+    assert issubclass(LLMResponseError, LLMError)
+
+
+def test_error_message_roundtrip():
+    e = LLMTimeoutError("timeout!")
+    assert str(e) == "timeout!"