fix: remove securityContext from UI pod — nginx needs root for setup

The standard nginx image requires root to modify /etc/nginx/conf.d
and create /var/cache/nginx directories during startup.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

deploy/base/ui.yaml

@@ -24,9 +24,6 @@ spec:
     spec:
       imagePullSecrets:
         - name: gitea-registry
-      securityContext:
-        runAsNonRoot: true
-        runAsUser: 101
       containers:
         - name: ui
           image: gitea.siegeln.net/cameleer/cameleer3-server-ui:latest