feat(alerts): severity + kind filter selects on Events tab

Operators can now narrow the history table by severity (INFO/WARNING/
ERROR/CRITICAL) and by alert kind (dynamically derived from loaded
events, searchable). Filtering is client-side — no extra API calls.
v1.1.112.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

management-ui/src/pages/Alerts/index.tsx

@@ -1,4 +1,4 @@
-import { useState } from 'react'
+import { useMemo, useState } from 'react'
 import {
   Alert, Button, Card, Form, Input, InputNumber, Modal, Popconfirm, Select, Space, Switch, Table, Tabs, Tag, Tooltip, Typography, message,
 } from 'antd'
@@ -88,6 +88,20 @@ export default function AlertsPage() {
   const [edit, setEdit] = useState<Channel | null>(null)
   const [creating, setCreating] = useState(false)
   const [form] = Form.useForm<ChannelFormValues>()
+  const [filterSev, setFilterSev] = useState<string | undefined>()
+  const [filterKind, setFilterKind] = useState<string | undefined>()
+
+  const kindOptions = useMemo(() => {
+    const kinds = [...new Set((events.data ?? []).map(e => e.kind))].sort()
+    return kinds.map(k => ({ value: k, label: k }))
+  }, [events.data])
+
+  const filteredEvents = useMemo(() =>
+    (events.data ?? []).filter(e =>
+      (!filterSev  || e.severity === filterSev) &&
+      (!filterKind || e.kind === filterKind)
+    ),
+  [events.data, filterSev, filterKind])
 
   function buildPayload(v: ChannelFormValues): Channel {
     const settings: Record<string, unknown> = {}
@@ -325,8 +339,32 @@ export default function AlertsPage() {
           label: t('alerts.tabs.events'),
           children: (
             <Card size="small">
+              <Space className="mb-8">
+                <Select
+                  allowClear
+                  placeholder={t('alerts.col.severity')}
+                  style={{ width: 150 }}
+                  value={filterSev}
+                  onChange={setFilterSev}
+                  options={[
+                    { value: 'info',     label: <Tag color="blue">INFO</Tag> },
+                    { value: 'warning',  label: <Tag color="orange">WARNING</Tag> },
+                    { value: 'error',    label: <Tag color="red">ERROR</Tag> },
+                    { value: 'critical', label: <Tag color="magenta">CRITICAL</Tag> },
+                  ]}
+                />
+                <Select
+                  allowClear
+                  showSearch
+                  placeholder={t('alerts.col.kind')}
+                  style={{ width: 220 }}
+                  value={filterKind}
+                  onChange={setFilterKind}
+                  options={kindOptions}
+                />
+              </Space>
               <Table size="small" rowKey="id" loading={events.isFetching}
-                dataSource={events.data ?? []} columns={evColumns}
+                dataSource={filteredEvents} columns={evColumns}
                 pagination={{ pageSize: 25 }}
                 locale={{ emptyText: (
                   <EmptyState