feat(chart): backup CronJob keys S3 off instance.id (code fallback)

values.yaml

@@ -9,6 +9,13 @@ instance:
   # Short slug used in K8s object names + as the Helm release name.
   # Must be DNS-safe (lowercase, no underscores, <= 40 chars).
   code: demo
+  # id -- durable instance identity, `<code>-<shortid>`. Written by
+  # Tower at create time (and backfilled onto existing instances).
+  # The backup CronJob uses it as the S3 key prefix so a deleted +
+  # recreated instance never inherits the previous one's snapshots.
+  # Empty in a bare `helm template` lint -- the CronJob falls back to
+  # `code` then.
+  id: ""
   # The full HTTPS hostname this instance answers on.
   # Tenants live under *.tenants.odoosky.org (covered by wildcard DNS A).
   domain: demo.tenants.odoosky.org