feat: complete Loki query, insights, settings and deployment workflows

Add the Loki query UI, access policies, ingress insights, alert and registry settings, and their backend APIs. Include the related Kubernetes deployment and collector updates required by the integrated application.

Validated with go test ./..., npm run build, and npm run lint.

frontend/src/pages/logs/components/SearchableValueSelect.tsx

@@ -0,0 +1,66 @@
+import { useEffect, useId, useRef, useState } from 'react'
+import { Input } from '@/components/ui/input'
+
+interface SearchableValueSelectProps {
+  label: string
+  values: string[]
+  value: string
+  onChange: (value: string) => void
+  placeholder?: string
+  allowEmpty?: boolean
+  loading?: boolean
+  disabled?: boolean
+}
+
+/** A searchable single-value combobox for Loki label values. */
+export function SearchableValueSelect({ label, values, value, onChange, placeholder, allowEmpty = false, loading = false, disabled = false }: SearchableValueSelectProps) {
+  const [open, setOpen] = useState(false)
+  const [filter, setFilter] = useState('')
+  const [active, setActive] = useState(0)
+  const root = useRef<HTMLDivElement>(null)
+  const id = useId()
+  const choices = values.filter(item => item.toLowerCase().includes(filter.toLowerCase()))
+
+  useEffect(() => {
+    const close = (event: MouseEvent) => {
+      if (!root.current?.contains(event.target as Node)) setOpen(false)
+    }
+    document.addEventListener('mousedown', close)
+    return () => document.removeEventListener('mousedown', close)
+  }, [])
+
+  function choose(next: string) {
+    onChange(next)
+    setFilter('')
+    setActive(0)
+    setOpen(false)
+  }
+
+  return <div ref={root} className="relative min-w-48">
+    <label className="block text-sm font-medium mb-1" htmlFor={id}>{label}</label>
+    <Input
+      id={id}
+      role="combobox"
+      aria-autocomplete="list"
+      aria-expanded={open}
+      aria-controls={`${id}-options`}
+      disabled={disabled}
+      value={open ? filter : value}
+      placeholder={placeholder ?? '搜索并选择'}
+      onFocus={() => { setFilter(''); setOpen(true) }}
+      onChange={event => { setFilter(event.target.value); setActive(0); setOpen(true) }}
+      onKeyDown={event => {
+        if (event.key === 'Escape') setOpen(false)
+        if (event.key === 'ArrowDown') { event.preventDefault(); setActive(current => Math.max(0, Math.min(current + 1, choices.length - 1))) }
+        if (event.key === 'ArrowUp') { event.preventDefault(); setActive(current => Math.max(0, current - 1)) }
+        if (event.key === 'Enter' && open && choices[active]) { event.preventDefault(); choose(choices[active]) }
+      }}
+    />
+    {open && <div id={`${id}-options`} role="listbox" className="absolute z-30 mt-1 max-h-56 w-full overflow-auto rounded-md border bg-popover p-1 shadow-lg">
+      {allowEmpty && <button type="button" role="option" aria-selected={!value} className="block w-full rounded px-2 py-1.5 text-left text-sm hover:bg-muted" onMouseDown={event => event.preventDefault()} onClick={() => choose('')}>不限</button>}
+      {loading ? <p className="px-2 py-1.5 text-sm text-muted-foreground">加载中…</p> : choices.length === 0 ? <p className="px-2 py-1.5 text-sm text-muted-foreground">无匹配值</p> : choices.slice(0, 200).map((item, index) =>
+        <button key={item} type="button" role="option" aria-selected={item === value} className={`block w-full rounded px-2 py-1.5 text-left text-sm ${index === active ? 'bg-primary/10 text-primary' : 'hover:bg-muted'}`} onMouseDown={event => event.preventDefault()} onClick={() => choose(item)}>{item}</button>
+      )}
+    </div>}
+  </div>
+}