fix(ui): сохранить контекст и фокус контейнеров

app/(main)/containers/page.tsx

@@ -1,6 +1,8 @@
 "use client"
 
-import { useCallback, useEffect, useMemo, useRef, useState } from "react"
+import { Suspense, useCallback, useEffect, useMemo, useRef, useState } from "react"
+import { useSearchParams } from "next/navigation"
+import { readContainersUrl, patchContainersUrl, type ContainerStatusFilter } from "@/lib/containers-url-state"
 import { PageHeader } from "@/components/page-header"
 import { routerContainers as mockContainers, servers as mockServers } from "@/lib/data"
 import type { RouterContainer, Server } from "@/lib/data"
@@ -98,6 +100,7 @@ function ExportSheet({ selection, onClose }: {selection: ContainerExport | null;
   return <CodeExportSheet open={!!selection} onClose={onClose} title="Снимок контейнера" description="Данные каталога; конфигурация устройства и резервная копия в снимок не входят."
     className="data-[side=right]:w-full data-[side=right]:sm:max-w-xl min-w-0 [&_[data-slot=sheet-footer]]:flex-wrap"
     beforeCode={<p className="text-xs text-muted-foreground">{selection?.source === "mock" ? "Демонстрационные данные." : "Чтение RouterOS: " + (selection?.collectedAt ? new Date(selection.collectedAt).toLocaleString("ru-RU") : "время неизвестно")}{selection?.failures.length ? " Настройки получены частично; ошибки включены в JSON." : ""}</p>}
+    returnFocus={() => Array.from(document.querySelectorAll<HTMLButtonElement>("button[aria-label]")).find(button => button.getAttribute("aria-label") === "Действия контейнера " + selection?.container.name) ?? null}
     formats={formats} />
 }
 
@@ -240,7 +243,8 @@ function ContainerCard({
   )
 }
 
-export default function ContainersPage() {
+export default function ContainersPage() { return <Suspense fallback={<p role="status">Загрузка контекста контейнеров…</p>}><ContainersSource /></Suspense> }
+function ContainersSource() {
   const { mode, backendUrl, prefsHydrated } = useDataSource()
   if (!prefsHydrated) return <p role="status">Загрузка настроек контейнеров…</p>
   return <ContainersContent key={JSON.stringify([mode, backendUrl])} />
@@ -251,16 +255,35 @@ function ContainersContent() {
   const canRead = can("mm:dashboard:read")
   const canReadServers = can("mm:servers:read")
   const canWrite = can("mm:servers:write")
-  const [search, setSearch] = useState("")
-  const [statusFilter, setStatusFilter] = useState<ContainerView["status"] | "all">("all")
+  const params = useSearchParams()
+  const context = readContainersUrl(params)
+  const search = context.search
+  const statusFilter = context.status
+  const selectedServerId = context.server
+  const urlError = context.error
+  function writeContext(changes: Record<string, string | null>, replace = false) {
+    const href = patchContainersUrl(new URLSearchParams(window.location.search), changes) + window.location.hash
+    if (replace) window.history.replaceState(null, "", href); else window.history.pushState(null, "", href)
+  }
+  const setSearch = (value: string) => writeContext({ q: value }, true)
+  const setStatusFilter = (value: ContainerStatusFilter) => writeContext({ status: value === "all" ? null : value })
+  const setSelectedServerId = (value: string) => writeContext({ server: value === ALL_SERVERS_ID ? null : value })
   const [exportContainer, setExportContainer] = useState<ContainerExport | null>(null)
-  const [selectedServerId, setSelectedServerId] = useState(ALL_SERVERS_ID)
   const [state, setState] = useState<ContainersState | null>(null)
   const [lastStates, setLastStates] = useState<Record<number, ContainerServerState>>({})
   const [liveServers, setLiveServers] = useState<ContainerServer[]>([])
   const [loading, setLoading] = useState(isLive && (canRead || canReadServers))
   const [busyId, setBusyId] = useState<string | null>(null)
   const [deleteTarget, setDeleteTarget] = useState<ContainerView | null>(null)
+  const deleteReturnLabel = useRef<string | null>(null)
+  useEffect(() => {
+    if (deleteTarget || busyId || !deleteReturnLabel.current) return
+    const frame = requestAnimationFrame(() => {
+      const target = Array.from(document.querySelectorAll<HTMLButtonElement>("button[aria-label]")).find(button => button.getAttribute("aria-label") === deleteReturnLabel.current)
+      ;(target ?? Array.from(document.querySelectorAll<HTMLButtonElement>("button")).find(button => button.textContent?.trim() === "Обновить"))?.focus()
+    })
+    return () => cancelAnimationFrame(frame)
+  }, [deleteTarget, busyId])
   const [operationError, setOperationError] = useState<string | null>(null)
   const [operationNotice, setOperationNotice] = useState<string | null>(null)
   const [commandNeedsRead, setCommandNeedsRead] = useState(false)
@@ -309,7 +332,7 @@ function ContainersContent() {
   const relevantStates = state?.servers.filter(node => selectedServerId === ALL_SERVERS_ID || String(node.serverId) === selectedServerId)
   const known = !isLive || !!state && (selectedServerId === ALL_SERVERS_ID || !!relevantStates?.length) && relevantStates!.every(node => node.availability !== "error")
   const stale = isLive && !!liveError
-  const writeReady = !isLive || canWrite && !commandNeedsRead && !loading && !stale && !!serversReadAt && !serversError
+  const writeReady = !isLive || canWrite && !urlError && !commandNeedsRead && !loading && !stale && !!serversReadAt && !serversError
   const nodeFresh = (serverId: string) => !isLive || writeReady && state?.servers.some(node => String(node.serverId) === serverId && node.availability === "available" && displayServers.some(server => server.id === serverId))
   const scoped = useMemo(() => {
     if (effectiveServerId === ALL_SERVERS_ID) return displayContainers
@@ -391,6 +414,7 @@ function ContainersContent() {
       selectedId={effectiveServerId}
       onSelect={setSelectedServerId}
       showAll
+      preserveSelection
       allCount={displayServers.length}
       loading={isLive && loading && displayServers.length === 0}
       header={
@@ -418,6 +442,7 @@ function ContainersContent() {
     >
         <div className="flex flex-col min-w-0 gap-5 [overflow-wrap:anywhere]">
 
+          {urlError && <Alert role="alert" aria-label="Контекст контейнеров" variant="warning"><AlertDescription>{urlError}<Button type="button" variant="outline" onClick={() => writeContext({server:null,status:null,q:null})}>Сбросить контекст</Button></AlertDescription></Alert>}
           {operationNotice && <p role="status" className="text-sm [overflow-wrap:anywhere]">{operationNotice}</p>}
           {operationError && !deleteTarget && <Alert role="alert" aria-label="Команда контейнера" variant="warning"><AlertDescription>{operationError}</AlertDescription></Alert>}
           {isLive && !canRead && <p role="status">Для каталога контейнеров требуется mm:dashboard:read.</p>}
@@ -529,7 +554,7 @@ function ContainersContent() {
                   onStart={() => { void mutate(c, "start") }}
                   onStop={() => { void mutate(c, "stop") }}
                   onRestart={() => { void mutate(c, "restart") }}
-                  onRemove={() => { setOperationError(null); setDeleteTarget(c) }}
+                  onRemove={() => { deleteReturnLabel.current = "Действия контейнера " + c.name; setOperationError(null); setDeleteTarget(c) }}
                 />
               ))}
             </div>