Fix misleading password fallback message in build.sh

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

iso/builder/build.sh

@@ -82,7 +82,7 @@ else
         echo "SSH authorized_keys: $FOUND key(s) from ~/.keys/*.key.pub"
     else
         echo "WARNING: no SSH public keys found — falling back to password auth"
-        echo "  root password will be set to: bee / eeb"
+        echo "  SSH login: bee / eeb (user created by bee-sshsetup at boot)"
         echo "  (generate a key with: sh keys/scripts/keygen.sh <your-name>)"
         USE_PASSWORD_FALLBACK=1
     fi