feat(console): CHV executor option in dispatch/env selectors + experimental note in detail/list

- DispatchSection: add cloud-hypervisor option (labelled experimental,
  default off); default stays docker; hint states a KVM-host CHV worker
  must claim the task (otherwise it stays queued; attachments are
  rejected by the backend at creation) and that the frontend only passes
  the executor value through, never bypassing the backend allowlist.
- EnvSection: same option, because the backend env-create allowlist
  (local/docker/cloud-hypervisor) does allow it; note states env
  allowlist excludes cloud.
- TaskListSection: add cloud-hypervisor to the executor filter so CHV
  tasks are findable; list rows already showed executor.
- TaskDetailPanel: pure display note for cloud-hypervisor tasks
  (experimental, default off, no VM controls); detail already showed
  executor from the task API.
- README: document the CHV console entry, experimental marking, and
  verbatim backend-error display.
- Rebuilt cloud/console.html from src (tsc + vite single-file build);
  no backend change: executor is already returned by _task_to_dict.

cloud/console-react/src/sections/DispatchSection.tsx

@@ -106,12 +106,13 @@ export default function DispatchSection() {
           </select>
         ) : (
           <select aria-label="执行器" value={executor} onChange={(e) => setExecutor(e.target.value)}>
-            <option value="docker">docker（默认，多用户下隔离最强）</option><option value="local">local</option><option value="cloud">cloud</option>
+            <option value="docker">docker（默认，多用户下隔离最强）</option><option value="local">local</option><option value="cloud">cloud</option><option value="cloud-hypervisor">cloud-hypervisor（实验，默认关闭）</option>
           </select>
         )}
         <label><input type="checkbox" checked={goalMode} onChange={(e) => setGoalMode(e.target.checked)} /> goal 模式</label>
         <label><input type="checkbox" checked={planMode} onChange={(e) => setPlanMode(e.target.checked)} /> 计划模式（只读）</label>
       </Bar>
+      {executor === "cloud-hypervisor" ? <div className="muted">实验执行器，默认关闭：需后端已开启 CHV worker 且宿主有 KVM，否则任务无人认领、一直排队；带附件时建任务即被后端拒绝（错误文案原样显示在下方）。前端只传 executor 值，不绕过后端白名单；默认仍是 docker。</div> : null}
       <textarea className="prompt stacked" placeholder="任务 prompt（必填）" value={prompt} onChange={(e) => setPrompt(e.target.value)} />
       {isSide ? null : (<>
         <textarea className="coord stacked" placeholder="协调员子任务 JSON（可选），留空为普通任务" value={coordParts} onChange={(e) => setCoordParts(e.target.value)} />