Guidance 0.3.0

More model providers, better LARK exposure, re-done custom tools.

Breaking Changes

• Removed old-style @guidance-based tool calls (in favor of more generic OpenAI-style tools)
• Temp removal of calling support for local models (PR planned to restore support in-line with new tools)

Added

• Added support for groq and mistralai APIs via litellm
• Added experimental sglang model
• Added experimental chat_completion() and chat_completion_streaming() APIs to the engine class, to enable applying a Lark grammar to an LLM without using the DSL
• Added TTFT to model usage
• Added support for OpenAI-style tools:function tools (using JSON schemas for parameters)
• customtools including regex, lark, and (guidance native) grammar
• Added support for GPT-5

Changed

• Use official sentencepiece for Python 3.13, now that it is officially supported