auth-proxy: reusable ingress with auth proxy object for cue configs (#113)

affects: #110

Creates reusable auth proxy object in base cue config, and migrates rpuppy, url-shortener, pihole and memberships app to it.

Memberships app always requires authentication.
url-shortener now supports non-auth based interactions.
diff --git a/charts/url-shortener/values.yaml b/charts/url-shortener/values.yaml
index 3b0d837..dd3da7d 100644
--- a/charts/url-shortener/values.yaml
+++ b/charts/url-shortener/values.yaml
@@ -5,3 +5,4 @@
 storage:
   size: 1Gi
 portName: http
+requireAuth: false