Complete the v2 KeysAPI mutation surface

Complete the v2 KeysAPI mutation surface: a task in MiMo-V2.6-RL-harbor-code: MiMo-V2.6-RL Code (Harbor) (Harbor dataset). The current client.KeysAPI only exposes create, get, and watch operations, which means callers have to leave the typed client API for ordinary v2 key mutations. Extend this…