[FEATURE] Ability to switch context size for Kimi models

[divyeshio]

✨ The feature

https://www.kimi.com/code/docs/en/kimi-code/models

Kimi modesl now has option for 256k context size, we should add ability to select them.

🎯 The problem

Current picker does not allow picking context size

💡 Proposed solution

🔄 Alternatives considered

📋 Additional context