[Feature] Add Z.AI and Kimi 2 Models

[houko]

Description

Add Z.AI and Kimi 2 models to the provider list.

OpenFang Reference

• Original Issue: Add Z.AI and Kimi 2 models  RightNow-AI/openfang#419

Test Plan

• Z.AI model is available
• Kimi 2 model is available
• Both work correctly

[houko]

Implemented: Z.AI (zai provider) and Kimi 2 models registered in drivers/mod.rs and model_catalog.rs.