Specific endpoints (clone, reinstall, change-password) were being intercepted
by the generic /{action} handler because they were registered AFTER it.
Fix: move CloneRequest, ChangePasswordRequest models, _resolve_server,
_get_client_or_503 helpers, and all 5 specific endpoint functions BEFORE
the generic @router.post('.../{action}') handlers.
Remove duplicate definitions from the old 'Additional Instance Operations'
section at the end of the file.
5169bf80a3