The Kimi Coding plugin registers with provider ID `kimi` and default
model ID `kimi-code`, making the correct model ref `kimi/kimi-code`.
The docs incorrectly showed `kimi-coding/k2p5` as the provider/model
ref. This is confusing because `kimi-coding` is only a plugin alias,
not the actual provider ID used in config.
Updated all references in:
- docs/concepts/model-providers.md
- docs/providers/moonshot.md
- docs/zh-CN/concepts/model-providers.md
- docs/zh-CN/providers/moonshot.md