feat: add API key authentication support

- Added  `api_key` parameter to `SecureChatCompletion` and `send_secure_request`
- Implemented Bearer token authentication in request headers
- Updated test configuration to use API key
- Fixed missing newline at end of `.gitignore`

test.py

@@ -9,7 +9,7 @@ the same interface as OpenAI's ChatCompletion.create() method.
 import asyncio
 from nomyo import SecureChatCompletion
 
-client = SecureChatCompletion(base_url="http://localhost:12434", allow_http=True)
+client = SecureChatCompletion(api_key="test-api-key-12345")
 
 async def test_basic_chat():
     """Test basic chat completion with OpenAI-style API."""