Fix security warning reappearing after every reboot

Add two early-exit checks in sovran-legacy-security-check before the
legacy fallthrough block:
1. Exit if /var/lib/sovran/onboarding-complete exists (Hub onboarding done)
2. Exit if /var/lib/secrets/free-password exists and is not "free" (password changed)

This prevents the boot-time service from overwriting the security-status
file that /api/change-password clears after a successful password change.

Agent-Logs-Url: https://github.com/naturallaw777/staging_alpha/sessions/c18311e4-609d-4edf-a2a1-a018baede373

Co-authored-by: naturallaw777 <99053422+naturallaw777@users.noreply.github.com>

modules/core/factory-seal.nix

@@ -116,6 +116,15 @@ EOF
         exit 0
       fi
 
+      # If the user completed Hub onboarding, they've addressed security
+      [ -f /var/lib/sovran/onboarding-complete ] && exit 0
+
+      # If the free password has been changed from the factory default, no warning needed
+      if [ -f /var/lib/secrets/free-password ]; then
+        CURRENT=$(cat /var/lib/secrets/free-password)
+        [ "$CURRENT" != "free" ] && exit 0
+      fi
+
       # No flags at all + secrets exist = legacy (pre-seal era) machine
       if [ -f /var/lib/secrets/root-password ]; then
         mkdir -p /var/lib/sovran