Add bearer token support to API requests

[gromer]

This pull request introduces the use of bearer tokens for authentication in the OllamaKit API requests. The changes include adding a new bearerToken property to the OllamaKit struct and updating various methods to include this token when making API requests.

Key changes include:

Authentication Enhancement

• Added a bearerToken property to the OllamaKit struct and updated the initializer to accept this token. (Sources/OllamaKit/OllamaKit.swift) [1] [2]
• Updated the asURLRequest method in OKRouter to include the bearer token in the request headers if provided. (Sources/OllamaKit/Utils/OKRouter.swift)

API Request Updates

• Modified methods in various files to include the bearer token when creating URL requests:
  • chat method in OllamaKit+Chat.swift [1] [2]
  • copyModel method in OllamaKit+CopyModel.swift [1] [2]
  • deleteModel method in OllamaKit+DeleteModel.swift [1] [2]
  • embeddings method in OllamaKit+Embeddings.swift [1] [2]
  • generate method in OllamaKit+Generate.swift [1] [2]
  • modelInfo method in OllamaKit+ModelInfo.swift [1] [2]
  • models method in OllamaKit+Models.swift [1] [2]
  • pullModel method in OllamaKit+PullModel.swift [1] [2]
  • reachable method in OllamaKit+Reachable.swift [1] [2]

I'm still looking at this, and working on testing it, just wanted to get the initial code into PR form.

[kevinhermawan]

Suggestion, instead of creating a specific header for the bearer token, we can implement custom HTTP headers. You can check my implementation at swift-llm-chat-openai or swift-llm-chat-anthropic

[gromer]

Suggestion, instead of creating a specific header for the bearer token, we can implement custom HTTP headers. You can check my implementation at swift-llm-chat-openai or swift-llm-chat-anthropic

I agree. After making this PR, I got thinking about it. Since Ollama doesn't natively support an auth header, a more general header solution does seem the best route. I'll poke around at your other repos, and update this PR soon 🤘