v1.0.13

Handle 409 (node name already taken) during enrollment

If a user picks a node name that's already registered to another account, the installer now:

• Prints a clear message: "That node name is already taken by another account. Please choose a different name."
• Re-prompts for a new node name in-place (no need to restart the installer)
• Retries enrollment with the same token and new name
• Updates config.env automatically with the new name

All other errors (403, 500, etc.) still fail immediately with the existing error message.