Struct Transition 

pub struct Transition {
    pub target: String,
    pub guard: Arc<dyn Fn(&State) -> bool + Send + Sync>,
    pub description: Option<String>,
}

A guard-based transition to a named target phase.

Fields

target: String

Name of the target phase.

guard: Arc<dyn Fn(&State) -> bool + Send + Sync>

Guard function — transition fires when this returns true.

description: Option<String>

Optional human-readable description of when/why this transition fires. Used by describe_navigation() to tell the model what paths are available.