Release v2.2.0

- Add native Zulip notification support via zulip:// shoutrrr URLs (#271)
- Add ?messagekey= option for generic webhooks to rename the JSON payload
  field (#271)
- Change DELETE_ON_FAILURE default to false: preserve existing DNS records
  and skip WAF list updates when IP detection fails (#277)
- Document the local.iface.stable IPv6 provider and Helm chart added since
  v2.1.2

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Cargo.lock

@@ -92,7 +92,7 @@ dependencies = [
 
 [[package]]
 name = "cloudflare-ddns"
-version = "2.1.2"
+version = "2.2.0"
 dependencies = [
  "if-addrs",
  "rand",