plc-recovery-from-backuplisted

## When to Use - Restoring a controller after suspected or confirmed logic tampering. - Recovering a corrupted controller after a failed update or malware event. - Returning a controller to service after incident isolation. - Rolling forward after a vendor firmware issue is resolved. ## Prerequisites - Verified backup of the controller logic and configuration with `sha256sum` files. - A second known-good backup for the rollback plan. - Maintenance window approved by the operations manager. - Connection type and rack/slot data per the controller inventory. - python-snap7 or the vendor download tool for the platform. - Credentials: engineering access on the controller. - Authorization: operations manager approves the restore. Safety engineer confirms the process can tolerate the controller stopping. - Upstream skills: `plc-logic-integrity-check` for the baseline hash method. This skill reuses its verification approach. ### Safety This skill is active. Every step that touches the controller is gated in the Workflow section. - Active. Applies restores to live controllers. Requires operations manager approval, a safety engineer review, and a maintenance window. ## Workflow > SAFETY: If at any point the action risks human safety or process integrity, halt and escalate to the operations lead before continuing. 1. Verify backup integrity before any controller contact: `sha256sum -c backup.sha256` A failed check means the backup is untrusted. Do not restore from it. Fin