rig-core-v0.12.0

Added

• add gpt-image-1 (#418)
• multi-turn / reasoning loops + parallel tool calling (#370)

Fixed

• system and developer messages for openai (#430)
• o-series models + constants (#426)
• dynamically pull rag text from chat history (#425)
• rig tool macro struct not public (#409)
• function call conversion typo (#415)
• deepseek function call conversion typo (#414)

Other

• Donot use async closure + Bump mcp-core (#428)
• Remove broken xAI reference link in embedding.rs (#427)
• Style/trace gemini embedding (#411)
• Update agent_with_huggingface.rs (#401)