Refactor VM script to use shared vm-core helpers

Introduce a shared vm-core loader and refactor the Ubuntu 26.04 VM script to use reusable helper functions. misc/vm-core.func: add COMMUNITY_SCRIPTS_URL default and load_api_functions to dynamically source API helpers, then call load_api_functions from load_functions. vm/ubuntu2604-vm.sh: switch to sourcing the shared vm-core via COMMUNITY_SCRIPTS_URL, replace many inline UI and utility functions with generic vm_* helpers (vm_confirm_new_vm, vm_prompt_*, vm_select_storage, vm_define_disk_references, set_description, etc.), modernize quoting and pushd usage, simplify disk import/resizing logic, and set START_VM default to yes. Also update repository URLs to ProxmoxVED and adjust some behavior (machine type handling, storage/disk references). Overall this centralizes common functionality, reduces duplication, and prepares scripts to use the shared core utilities.

misc/vm-core.func

@@ -14,9 +14,18 @@ declare -A MSG_INFO_SHOWN
 [[ -n "${_CORE_FUNC_LOADED:-}" ]] && return
 _CORE_FUNC_LOADED=1
 
+COMMUNITY_SCRIPTS_URL="${COMMUNITY_SCRIPTS_URL:-https://git.community-scripts.org/community-scripts/ProxmoxVED/raw/branch/main}"
+
+load_api_functions() {
+  if ! declare -f post_to_api_vm >/dev/null 2>&1; then
+    source /dev/stdin <<<$(curl -fsSL "$COMMUNITY_SCRIPTS_URL/misc/api.func")
+  fi
+}
+
 load_functions() {
   [[ -n "${__FUNCTIONS_LOADED:-}" ]] && return
   __FUNCTIONS_LOADED=1
+  load_api_functions
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