Is my eastern redbud dying or just stressed?

Redbud decline is branch-by-branch rather than whole-tree — one limb wilts and browns in midsummer with the dead leaves hanging on, and there is a sunken, cracked, blackened canker where it meets live wood. Stress is leaf scorch or early yellowing in an August drought on a tree that flowers and leafs out fine the next April; dying is a second and third limb going the same way in consecutive years, driven by Botryosphaeria canker or verticillium wilt with brown streaking in the sapwood — neither responds to fungicide, so the honest conversation is staged removal, not treatment.