ForgeFlow 0.6.1

Windows source updater reliability

Fixes the Windows PowerShell 5.1 STARTED-handshake failure caused by replacing an already existing status file with Move-Item -Force.
Uses System.IO.File.Replace with an overwrite-copy fallback for deterministic status persistence.
Adds a handshake-only verification mode used by the local bootstrap overlay.
Keeps ForgeFlow open when startup cannot be proven and now includes the helper log tail in the visible error.
Requires the status updateId to match the current request, preventing an old status file from being accepted.
Records the actual restart PID after a successful update or rollback.