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/TaskListSection.tsx

@@ -38,7 +38,7 @@ export default function TaskListSection({ onNew }: { onNew: () => void }) {
           {["queued", "running", "completed", "failed", "interrupted", "merged", "merge-failed"].map((s) => <option key={s} value={s}>{s}</option>)}
         </select>
         <select aria-label="执行器筛选" value={ctx.executorFilter} onChange={(e) => ctx.setExecutorFilter(e.target.value)}>
-          <option value="">执行器：全部</option><option value="local">local</option><option value="docker">docker</option><option value="cloud">cloud</option>
+          <option value="">执行器：全部</option><option value="local">local</option><option value="docker">docker</option><option value="cloud">cloud</option><option value="cloud-hypervisor">cloud-hypervisor（实验）</option>
         </select>
       </div>
       <div className="bar">