chore: 更新项目配置文件和忽略规则

- 将.env.example重命名为.env-example并更新内容
- 清理.gitignore中不必要的规则
- 调整pyproject.toml中依赖和镜像源的顺序

.env-example

@@ -0,0 +1,2 @@
+# DeepSeek API Key
+DEEPSEEK_API_KEY=sk-xxxx

.env.example

@@ -1,2 +0,0 @@
-# DeepSeek API Key
-DEEPSEEK_API_KEY=your-key-here

.gitignore

@@ -4,5 +4,4 @@ __pycache__/
 .venv/
 .env
 .DS_Store
-models/*.pkl
 .pytest_cache/

pyproject.toml

@@ -4,11 +4,6 @@ version = "0.1.0"
 description = "机器学习 × LLM × Agent 课程设计模板"
 readme = "README.md"
 requires-python = ">=3.12"
-
-[[tool.uv.index]]
-url = "https://mirrors.aliyun.com/pypi/simple/"
-default = true
-
 dependencies = [
     "pydantic>=2.10",
     "pandera>=0.21",
@@ -23,6 +18,10 @@ dependencies = [
     "streamlit>=1.40",
 ]
 
+[[tool.uv.index]]
+url = "https://mirrors.aliyun.com/pypi/simple/"
+default = true
+
 [dependency-groups]
 dev = [
     "pytest>=8.0",