Add create item endpoint with test

app/main.py

@@ -38,6 +38,16 @@ async def list_items():
         ]
     }
 
+@app.post("/api/items")
+async def create_item(name: str, description: str):
+    """Create a new item."""
+    return {
+        "id": 999,
+        "name": name,
+        "description": description,
+        "created": True
+    }
+
 
 @app.get("/api/items/{item_id}")
 async def get_item(item_id: int):

tests/test_main.py

@@ -41,3 +41,12 @@ def test_get_item():
     assert data["id"] == 5
     assert data["name"] == "Item 5"
     assert "item number 5" in data["description"]
+
+def test_create_item():
+    response = client.post("/api/items?name=TestItem&description=A test item")
+    assert response.status_code == 200
+    data = response.json()
+    assert data["name"] == "TestItem"
+    assert data["description"] == "A test item"
+    assert data["created"] is True
+    assert data["id"] == 999