Function may_violate_diagnostics 

pub fn may_violate_diagnostics(
    agent: &AgentDecl,
    types: &HashMap<String, Arc<TypeDecl>>,
) -> Vec<CompileError>

#2221: bynk.transition.may_violate — a warning for each move a handler can make that a transition refuses at commit (track §3.2–§3.5).

Only Certainty::Known violations fire, from start states the agent can be in after a commit (the overlay already filters on StateMachine::reachable_after_commit); a computed write that only may land badly, a truncated handler and a transition outside the evaluated fragment raise nothing. The warning sits on the write (or, for an unchanged path, its tail), names the path’s guards, and carries the transition and one handler that makes the start state reachable as related information. The commit-time check is unchanged.