restore bin/controller.sh script within -E unbreak option

Sometime after unexpected failover and maybe assassin.sh startup the MySQL replication is healthy and restartable but no bin/controller.sh script exists.
Please add in check and rename of bin/controller.sh_disabled back to its original name also.

Start with bin/controller.sh_disabled and the -E unbreak path, then check how assassin.sh startup handles the missing script. Ensure the unbreak flow checks for bin/controller.sh and restores it from the disabled filename when needed; confirm the script is present after the recovery path completes.

Written by the indexing model from the issue text.