The current side becomes the working tree, so a divergent path compares what the operator actually has rather than what the check-in says is on disk -- which is the disagreement B-merge-14 existed to avoid. A clean tree scans to no divergences and every side reads from the store exactly as before.

Rollback needs no new machinery: captureMergeImages already reads the worktree, so an abandoned merge restores the uncommitted bytes.

Also adds the fault-injection coverage the carried update path was missing: a carried update that fails mid-apply must restore the WORKING bytes, not the check-in's. Verified by mutation -- breaking the baseline overlay fails both tests. closed check-in: 0627425be0 user: dmestas tags: merge-dirty-tree