Attribute Macro verb 

#[verb]

Attribute macro for registering a verb command

Usage:

#[verb("status")]
fn show_status() -> Result<Status> {}

Compile-Time Validation

This macro performs extensive compile-time validation:

• Return type must exist and implement Serialize
• Attribute syntax must be correct (helpful error messages)
• Duplicate verb registration detection
• Parameter attributes (#[arg]) must be valid