v1.1.1: Fix error state handling

• Fixes a bug where errors weren't being propagated through the stack correctly (manifested in #4).
• LlamaRunner.RunState.failed() is now created with an optional Error — this should be non-nil but because of the bridging with Objective-C/C++ there may be cases where this is not the case.

llama.swift → CameLLM:

• This is a maintenance update for llama.swift; all future feature development is happening at 🐪 CameLLM