Main renamed/refactored #tryShakeRescueForDeadEnd + #emitShakeRescueNotice into
the tiered #rescueCompactionDeadEnd (elide, then image drop, notices emitted
internally), so a textually-clean merge of this branch left calls to undefined
private methods. Re-express the !preparation rescue through the new API:
progress = prepareCompaction succeeding on the rewritten branch, skipElide when
falling through from a shake pass (the image tier still gets a chance), and
historyRewritten flagged whenever a tier freed content even without progress.
Restore the baseline dead-end remedy text (image drop is automated now, so the
manual /shake images suggestion is stale) and align the rescue-refit regression
test with main's continuation gating (auto-continue after compaction now
requires an active goal or queued work).
can1357
ba385a2946