refactor: extract userbot to standalone repo, add as git submodule

userbot now lives at ssh://git@gitssh.forust.xyz:2221/forust/userbot.git
and is included in homelab as a submodule at userbot/

userbot/k8s/overlays/dev/kustomization.yaml

@@ -1,8 +0,0 @@
-apiVersion: kustomize.config.k8s.io/v1beta1
-kind: Kustomization
-
-resources:
-  - ../../base
-
-patches:
-  - path: patch-downloads.yaml