Function sign_map_has_conflicts 

pub fn sign_map_has_conflicts(sign_map: &DiffSignMap) -> bool

DX.8 (2026-06-24): the diff-conflict-mode activation predicate.

A diff session warrants conflict resolution iff its published sign map carries at least one crate::overlay::DiffSignKind::Conflict region. A pure function over the sign map — trivially testable and safe to consult anywhere — so the bridge can gate diff-conflict-mode activation on it (follow-up) the same way DiffModeBridge gates diff-mode on session participation.