参考所有分组，完成尽量多的内容。禁止顺手扩功能 smoke

结论：收敛第 1 组 switchkins/remap 生成器约束，--all-output-dir 拒绝含空白路径和文件系统根目录，避免生成表/配置 case 误写到不受控位置；未扩展 smoke 功能。验证：./check-linuxcnc-switchkins-remap-table.sh linuxcnc-kinematics-source-files.txt、CNC_SIM_ALL_NATIVE_GUARDRAILS_ONLY=1 ./test-all-native.sh、./test-native.sh、./test-linuxcnc-source-link.sh 均通过。

generate-linuxcnc-switchkins-remap-table.sh

@@ -64,6 +64,10 @@ if [[ "$mode" == all && -z "$all_output_dir" ]]; then
     echo "missing output directory for --all-output-dir" >&2
     exit 1
 fi
+if [[ "$mode" == all && "$all_output_dir" =~ [[:space:]] ]]; then
+    echo "switchkins remap output directory must not contain whitespace: $all_output_dir" >&2
+    exit 1
+fi
 
 linuxcnc_root=$(cd "$linuxcnc_root" && pwd)
 
@@ -1244,6 +1248,11 @@ elif [[ "$mode" == all ]]; then
         exit 1
     fi
     mkdir -p "$all_output_dir"
+    all_output_dir=$(cd "$all_output_dir" && pwd)
+    if [[ "$all_output_dir" == "/" ]]; then
+        echo "switchkins remap output directory must not be the filesystem root" >&2
+        exit 1
+    fi
     write_generated_file "$all_output_dir/linuxcnc_switchkins_remap_table.inc" "table" write_table
     write_generated_file "$all_output_dir/linuxcnc_switchkins_remap_config_cases.inc" "config cases" write_config_cases
     write_generated_file "$all_output_dir/linuxcnc_switchkins_remap_config_cases.json" "JSON config cases" write_json_cases