Feature Request: Add non-interactive kimi plugins CLI command for plugin management

Problem

Currently, plugin management in Kimi Code CLI is only available through the interactive TUI via /plugins. There is no way to install, list, enable/disable, or remove plugins from shell scripts, CI pipelines, or when the user prefers not to open the TUI.

Proposed Solution

Add a kimi plugins subcommand that mirrors the TUI /plugins functionality:

• kimi plugins list [--json]
• kimi plugins info <id> [--json]
• kimi plugins install <source> [-y/--yes]
• kimi plugins remove <id> [-y/--yes]
• kimi plugins enable <id>
• kimi plugins disable <id>
• kimi plugins marketplace [--registry <name-or-url>] [--json]
• kimi plugins registry list [--json]
• kimi plugins registry add <url> [--name <name>]
• kimi plugins registry remove <name-or-url>

Use Cases

• Provisioning a new machine with a standard set of plugins.
• Installing plugins in CI/CD pipelines.
• Managing plugin state without entering the TUI.

Additional Context

A custom registry system would also be useful for teams that want to maintain an internal plugin marketplace alongside the official one.

Start by locating the existing TUI /plugins implementation and tracing how plugin installation, listing, state changes, and registries are handled. Define the non-interactive command behavior and JSON, confirmation, and registry options; done means all listed kimi plugins subcommands work without opening the TUI.