fix(a11y): silence live stats and make Select tags removable for screen readers

Ant Design's Spin wraps its content in aria-live="polite", so every
WebSocket tick on the dashboard, inbounds, clients and nodes pages was
announced, and only the changed number was read, with no label.
Pass aria-live="off" on every Spin that wraps content; aria-busy still
signals loading. Each vital tile is now a group named by its metric,
so "47.2 %" is read as CPU.

rc-select renders each tag's remove "x" as an aria-hidden span with no
tabIndex, so screen-reader users could only Backspace the last value
away, never remove one SNI or inbound from the middle.
selectTagRender swaps in a real button named "Remove <value>" and
moves focus to the next tag after removal. It is applied to every
tags/multiple Select. maxTagCount="responsive" is dropped because it
hid selected inbounds behind "+N", where no screen reader could reach
them.

Two oxlint rules (antd-a11y/spin-content-not-live and
antd-a11y/select-tag-remove) keep new code from regressing either fix.

frontend/src/components/form/index.ts

@@ -7,3 +7,4 @@ export { default as CipherSuitesSelect } from './CipherSuitesSelect';
 export { default as RemarkTemplateField } from './RemarkTemplateField';
 export { default as RemarkVarPicker } from './RemarkVarPicker';
 export { default as CustomSockoptList } from '../../lib/xray/forms/transport/CustomSockoptList';
+export { selectTagRender } from './SelectTag';