Per design invariant (a controller exits only on crash or admin kill), replace the
self-abort recovery terminal (tasks 3.3/4.3/4.4) with a loud, permanent, non-promotable
fence that stays alive and keeps retrying catch-up (self-heals on peer return; no manual
admin recovery). Records the never-self-terminate invariant as project-wide guidance in
src/controller/CLAUDE.md + .kiro/steering/ha-async-io.md.
Full controller suite green under ASAN (508 PASS / 0 FAIL / 0 sanitizer
aborts, independently re-censused). All 16 tasks complete; barrier
before reply proven across all restructured opcodes; classification
guard active; barrier-before-state-removal precondition for
ha-single-leader-role satisfied. spec phase=implemented; roadmap
updated. Sub-spec 2 of 4 of the ha-consistency-invariants umbrella.