参考所有分组，完成尽量多的内容：收紧 manifest 坏行校验

结论：通用 LinuxCNC manifest lister 现在与输入校验一致拒绝缺少 note 或字段数量异常的坏行，并在 all-native guardrail 中覆盖通用 lister 与 native/source-link 调用链；未扩展 smoke 功能。

list-linuxcnc-manifest-sources.sh

@@ -44,13 +44,20 @@ case "$output_mode" in
 esac
 
 seen_sources=()
-while IFS=: read -r group path note; do
-    case "$group" in
+manifest_line_number=0
+while IFS= read -r manifest_line || [[ -n "$manifest_line" ]]; do
+    manifest_line_number=$((manifest_line_number + 1))
+    case "$manifest_line" in
         ""|\#*)
             continue
             ;;
     esac
 
+    IFS=: read -r group path note extra <<<"$manifest_line"
+    if [[ -z "$group" || -z "$path" || -z "$note" || -n "${extra:-}" ]]; then
+        echo "bad manifest line $manifest_line_number: $manifest_line" >&2
+        exit 1
+    fi
     if ! contains_group "$allowed_groups" "$group"; then
         echo "unknown manifest group: $group" >&2
         exit 1