[CLI] Sandbox ID should be called Routing Key

[foxish]

For 1.1

signadot sb get pr-263-location
ID:               22rutzjfl9uy8
Name:             pr-263-location
Description:      sandbox for "location" service
Cluster:          demo
Created:          Fri, 07 Feb 2025 07:52:56 PST (5 months ago)
Updated:          Tue, 08 Jul 2025 12:06:01 PDT (12 days ago)
TTL:              - (forever)
Dashboard page:   https://app.signadot.com/sandbox/name/pr-263-location
Status:           Ready (AllDesiredWorkloadsReady: All desired workloads are available.)

cc @scott-cotton @davixcky