feat(k8s): add Keel annotations and update anubis image tag

Configure automatic updates with Keel by adding annotations for polling,
update policy, and tag matching. Also update anubis container to use
:main tag instead of :latest for consistent versioning.

Author: Xe

manifest/xesite/deployment.yaml

@@ -72,7 +72,7 @@ spec:
             initialDelaySeconds: 30
             periodSeconds: 30
         - name: anubis
-          image: ghcr.io/techarohq/anubis:latest
+          image: ghcr.io/techarohq/anubis:main
           imagePullPolicy: Always
           env:
             - name: "BIND"