refactor: 重命名 command checker 为 cmd checker 并适配跨平台测试

将 type/configKey 从 "command" 统一为 "cmd"，源码目录 runner/command/ → runner/cmd/，
spec 目录 command-checker/ → cmd-checker/，测试全部改用 bun -e 替代 Unix 系统命令，
归档 cmd-checker-enhancement 变更并同步 delta spec 到主 spec。

tests/web/constants/target-table-columns.test.ts

@@ -34,7 +34,7 @@ function makeTarget(overrides: Partial<TargetStatus> = {}): TargetStatus {
 
 describe("createTargetTableColumns", () => {
   test("生成 7 个目标表格列", () => {
-    const columns = createTargetTableColumns(["http", "command"]);
+    const columns = createTargetTableColumns(["http", "cmd"]);
 
     expect(columns.map((column) => column.colKey)).toEqual([
       "latestCheck.matched",
@@ -48,14 +48,14 @@ describe("createTargetTableColumns", () => {
   });
 
   test("根据 checkerTypes 生成类型筛选器", () => {
-    const typeColumn = getColumn(createTargetTableColumns(["http", "command", "tcp"]), "type");
+    const typeColumn = getColumn(createTargetTableColumns(["http", "cmd", "tcp"]), "type");
     const filter = typeColumn.filter as TableFilter;
 
     expect(filter.type).toBe("single");
     expect(filter.list).toEqual([
       { label: "全部", value: "" },
       { label: "http", value: "http" },
-      { label: "command", value: "command" },
+      { label: "cmd", value: "cmd" },
       { label: "tcp", value: "tcp" },
     ]);
   });