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/pages/index/GeodataSection.tsx

@@ -178,7 +178,7 @@ export default function GeodataSection({ active, onBusy, onClose }: GeodataSecti
     <div>
       {modalContextHolder}
       {messageContextHolder}
-      <Spin spinning={loading}>
+      <Spin aria-live="off" spinning={loading}>
         <Alert type="info" className="mb-12" title={t('pages.index.geodataHint')} showIcon />
         <Form layout="vertical">
           <Form.Item

frontend/src/pages/index/IndexPage.tsx

@@ -174,6 +174,7 @@ export default function IndexPage() {
         <Layout className="content-shell">
           <Layout.Content className="content-area">
             <Spin
+              aria-live="off"
               spinning={loading || !fetched}
               delay={200}
               description={loading ? loadingTip : t('loading')}

frontend/src/pages/index/VersionModal.tsx

@@ -103,7 +103,7 @@ export default function VersionModal({ open, status, onClose, onBusy }: VersionM
   return (
     <Modal open={open} title={t('pages.index.xrayUpdates')} footer={null} onCancel={onClose}>
       {modalContextHolder}
-      <Spin spinning={loading}>
+      <Spin aria-live="off" spinning={loading}>
         <Collapse
           accordion
           activeKey={activeKey}

frontend/src/pages/index/VitalTile.tsx

@@ -1,4 +1,4 @@
-import { useMemo } from 'react';
+import { useId, useMemo } from 'react';
 import type { ReactNode } from 'react';
 import { Card, theme } from 'antd';
 
@@ -31,6 +31,7 @@ export default function VitalTile({
   isMobile,
 }: VitalTileProps) {
   const { token } = theme.useToken();
+  const labelId = useId();
   const meanColor = token.colorTextTertiary;
 
   const referenceLines = useMemo(
@@ -39,10 +40,18 @@ export default function VitalTile({
   );
 
   return (
-    <Card hoverable className="ov-tile" styles={{ body: { padding: 0 } }}>
+    <Card
+      hoverable
+      className="ov-tile"
+      styles={{ body: { padding: 0 } }}
+      role="group"
+      aria-labelledby={labelId}
+    >
       <div className="ov-tile-head">
         <span className="ov-tile-icon">{icon}</span>
-        <span className="ov-kicker">{label}</span>
+        <span className="ov-kicker" id={labelId}>
+          {label}
+        </span>
       </div>
 
       <div className="ov-tile-value">