Set default ProxmoxVE raw URL in UPS script

Define `_CS_DEFAULT_URL` at the top of `ct/pve-ups.sh` and remove the outdated bootstrap comments, aligning the script with the newer URL-default pattern used for script sourcing.

CHANGELOG.md

@@ -536,6 +536,10 @@ Exercise vigilance regarding copycat or coat-tailing sites that seek to exploit
 
     - docuseal: use DocuSeal's patched PDFium build to fix service start [@MickLesk](https://github.com/MickLesk) ([#16673](https://github.com/community-scripts/ProxmoxVE/pull/16673))
 
+  - #### ✨ New Features
+
+    - update authentik to 2026.8.0 [@thieneret](https://github.com/thieneret) ([#16674](https://github.com/community-scripts/ProxmoxVE/pull/16674))
+
 ## 2026-08-21
 
 ### 🚀 Updated Scripts

ct/pve-ups.sh

@@ -1,7 +1,5 @@
 #!/usr/bin/env bash
-# Engine comes from community-scripts/core; this repo only ships the scripts.
-# A local core checkout wins (COMMUNITY_SCRIPTS_CORE_DIR, else a sibling ../core),
-# so a fork or branch of core can be tested without editing this file.
+_CS_DEFAULT_URL="https://raw.githubusercontent.com/community-scripts/ProxmoxVE/main"
 _cs_boot="${COMMUNITY_SCRIPTS_CORE_DIR:-$(dirname "${BASH_SOURCE[0]}")/../../core}/core/build.func"
 source "$_cs_boot" 2>/dev/null || source <(curl -fsSL "${COMMUNITY_SCRIPTS_CORE_URL:-https://raw.githubusercontent.com/community-scripts/core/main}/core/build.func")
 # Copyright (c) 2021-2026 community-scripts ORG