feat(hook): add noReply option to command.execute.before hook

[arismoko]

Summary

• Adds noReply?: boolean to the command.execute.before hook output type
• Passes hookOutput.noReply to prompt() to skip LLM when set

Use Case

Plugins can handle slash commands directly without invoking the LLM.

Verification

Tested with a plugin that handles /tty commands. Setting output.noReply = true in the hook skips LLM invocation and the command output is displayed directly.

Fixes #9306