feat: 初始化FastAPI项目基础框架

添加项目基础结构，包括：
- 核心模块(src/main.py)
- 路由模块(users/items)
- 数据库配置和模型
- 日志工具
- 测试用例
- 项目文档和依赖配置

tests/test_users.py

@@ -0,0 +1,92 @@
+import pytest
+from fastapi.testclient import TestClient
+from src.main import app
+
+client = TestClient(app)
+
+def test_create_user():
+    response = client.post(
+        "/users/",
+        json={
+            "email": "test@example.com",
+            "first_name": "Test",
+            "last_name": "User",
+            "password": "testpassword"
+        }
+    )
+    assert response.status_code == 201
+    data = response.json()
+    assert data["email"] == "test@example.com"
+    assert "id" in data
+
+def test_read_users():
+    response = client.get("/users/")
+    assert response.status_code == 200
+    data = response.json()
+    assert isinstance(data, list)
+
+def test_read_user():
+    # First create a user
+    response = client.post(
+        "/users/",
+        json={
+            "email": "test2@example.com",
+            "first_name": "Test2",
+            "last_name": "User2",
+            "password": "testpassword"
+        }
+    )
+    assert response.status_code == 201
+    user_id = response.json()["id"]
+    
+    # Then read the user
+    response = client.get(f"/users/{user_id}")
+    assert response.status_code == 200
+    data = response.json()
+    assert data["id"] == user_id
+
+def test_update_user():
+    # First create a user
+    response = client.post(
+        "/users/",
+        json={
+            "email": "test3@example.com",
+            "first_name": "Test3",
+            "last_name": "User3",
+            "password": "testpassword"
+        }
+    )
+    assert response.status_code == 201
+    user_id = response.json()["id"]
+    
+    # Then update the user
+    response = client.put(
+        f"/users/{user_id}",
+        json={
+            "email": "updated@example.com",
+            "first_name": "Updated",
+            "last_name": "User",
+            "password": "updatedpassword"
+        }
+    )
+    assert response.status_code == 200
+    data = response.json()
+    assert data["email"] == "updated@example.com"
+
+def test_delete_user():
+    # First create a user
+    response = client.post(
+        "/users/",
+        json={
+            "email": "test4@example.com",
+            "first_name": "Test4",
+            "last_name": "User4",
+            "password": "testpassword"
+        }
+    )
+    assert response.status_code == 201
+    user_id = response.json()["id"]
+    
+    # Then delete the user
+    response = client.delete(f"/users/{user_id}")
+    assert response.status_code == 204