Add persistent action status banner and fix stacked toast overlap

Stack actions (start/stop/pull/update/…) now surface a dismissible
status banner on the stack detail page instead of relying on the
transient top-right toast alone. Also enable toast expand mode so
multiple notifications no longer collapse behind each other.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016pMmFFkdfxkoYjcEcpZTa5

frontend/src/pages/StackDetail.tsx

@@ -17,6 +17,7 @@ import { Badge, Button, Card, Input, Spinner, StatusDot } from "@/components/ui"
 import { ConfirmDialog } from "@/components/ui/ConfirmDialog";
 import { LogViewer } from "@/components/stacks/LogViewer";
 import { ContainerCard } from "@/components/stacks/ContainerCard";
+import { ActionStatusBanner } from "@/components/stacks/ActionStatusBanner";
 import { AutoUpdatePanel } from "@/components/stacks/AutoUpdatePanel";
 import { SecretsPanel } from "@/components/stacks/SecretsPanel";
 import { BackupButton } from "@/components/stacks/BackupRestore";
@@ -91,6 +92,10 @@ export function StackDetail() {
         )}
       </div>
 
+      {actions.status && (
+        <ActionStatusBanner status={actions.status} onDismiss={actions.dismissStatus} />
+      )}
+
       {/* Tabs */}
       <div className="flex gap-1 border-b border-slate-200 dark:border-slate-700">
         {TABS.map((t) => (