feat(App, DevicesPage): implement toast notifications for save status and update DevicesPage UI

src/app/App.tsx

@@ -1,6 +1,6 @@
 import { useEffect, useState } from 'react';
-import { Cpu, Settings, Wifi, Network, HardDrive, Activity, Search, Wrench, User, LogOut, Bell, FileText, AppWindow, Folder, Edit, Eye, Database, Upload, Download, Code2, LayoutList, Image, ChevronLeft, Loader2, Check, AlertCircle, RefreshCw, Terminal, Link, Printer, Maximize2, Minimize2 } from 'lucide-react';
+import { Cpu, Settings, Wifi, Network, HardDrive, Activity, Search, Wrench, User, LogOut, Bell, FileText, AppWindow, Folder, Edit, Eye, Database, Upload, Download, Code2, LayoutList, Image, ChevronLeft, Loader2, Terminal, Link, Printer, Maximize2, Minimize2 } from 'lucide-react';
-import { Toaster } from 'sonner';
+import { Toaster, toast } from 'sonner';
 import StatusPage from './components/StatusPage';
 import DevicesPage from './components/DevicesPage';
 import GeneralPage from './components/GeneralPage';
@@ -49,6 +49,28 @@ export default function App() {
   const [devicesOpenId, setDevicesOpenId] = useState<string | null>(null);
   const [isFullscreen, setIsFullscreen] = useState(false);
 
+  useEffect(() => {
+    const id = 'save-status';
+    switch (saveStatus) {
+      case 'idle':    toast.dismiss(id); break;
+      case 'loading': toast.loading('Loading settings…', { id }); break;
+      case 'unsaved':
+        toast(`${pendingCount} unsaved change${pendingCount === 1 ? '' : 's'}`, {
+          id, duration: Infinity,
+          action: { label: 'Save', onClick: flushNow },
+        });
+        break;
+      case 'saving':  toast.loading('Saving…', { id }); break;
+      case 'saved':   toast.success('Settings saved', { id, duration: 2000 }); break;
+      case 'error':
+        toast.error('Save failed', {
+          id, duration: Infinity,
+          action: { label: 'Retry', onClick: reload },
+        });
+        break;
+    }
+  }, [saveStatus, pendingCount, flushNow, reload]);
+
   useEffect(() => {
     const onChange = () => setIsFullscreen(!!document.fullscreenElement);
     document.addEventListener('fullscreenchange', onChange);
@@ -231,7 +253,6 @@ function AppPage({ title, onBack }: { title: string; onBack: () => void }) {
             >
               <AppWindow className="w-5 h-5 text-white" />
             </button>
-            <SaveStatusBadge status={saveStatus} pendingCount={pendingCount} onSave={flushNow} onReload={reload} />
             <div className="relative">
               <button
                 onClick={() => setShowProfileMenu(!showProfileMenu)}
@@ -336,73 +357,3 @@ function AppPage({ title, onBack }: { title: string; onBack: () => void }) {
   );
 }
 
-/**
- * Tiny indicator that reflects the current save status of the settings
- * file. Renders nothing when idle (so it doesn't clutter the header).
- */
-function SaveStatusBadge({
-  status,
-  pendingCount,
-  onSave,
-  onReload,
-}: {
-  status: 'idle' | 'loading' | 'unsaved' | 'saving' | 'saved' | 'error';
-  pendingCount: number;
-  onSave: () => void;
-  onReload: () => void;
-}) {
-  if (status === 'idle') return null;
-
-  if (status === 'loading') {
-    return (
-      <span className="text-xs text-white/80 inline-flex items-center gap-1" title="Loading settings from /.sys/config.json">
-        <Loader2 className="w-3 h-3 animate-spin" /> Loading
-      </span>
-    );
-  }
-
-  if (status === 'unsaved') {
-    return (
-      <span className="inline-flex items-center gap-1">
-        <span className="text-xs text-amber-300" title={`${pendingCount} unsaved change${pendingCount === 1 ? '' : 's'}`}>
-          {pendingCount} unsaved
-        </span>
-        <button
-          onClick={onSave}
-          className="text-xs bg-amber-500 hover:bg-amber-400 text-white px-2 py-0.5 rounded"
-          title="Save now"
-        >
-          Save
-        </button>
-      </span>
-    );
-  }
-
-  if (status === 'saving') {
-    return (
-      <span className="text-xs text-white/80 inline-flex items-center gap-1" title="Saving to /.sys/config.json">
-        <Loader2 className="w-3 h-3 animate-spin" /> Saving
-      </span>
-    );
-  }
-
-  if (status === 'saved') {
-    return (
-      <span className="text-xs text-white/80 inline-flex items-center gap-1" title="Saved to /.sys/config.json">
-        <Check className="w-3 h-3" /> Saved
-      </span>
-    );
-  }
-
-  // error
-  return (
-    <button
-      onClick={onReload}
-      className="text-xs text-red-300 hover:text-white inline-flex items-center gap-1"
-      title="Failed to save to /.sys/config.json — click to retry"
-    >
-      <AlertCircle className="w-3 h-3" /> Save failed
-      <RefreshCw className="w-3 h-3" />
-    </button>
-  );
-}

src/app/components/DevicesPage.tsx

@@ -340,14 +340,14 @@ export default function DevicesPage({ config, setConfig, openDeviceId, onClearOp
             <div className={`absolute top-0.5 w-5 h-5 bg-white rounded-full transition-transform ${cassette.enabled ? 'translate-x-6' : 'translate-x-0.5'}`} />
           </button>
         </div>
-        <div className="p-4">
+        {/* <div className="p-4">
           <label className="text-sm text-neutral-500 block mb-2">Play/Record</label>
           <input type="text" value={cassette.play_record || ''} onChange={(e) => updateSetting(['cassette', 'play_record'], e.target.value)} className="w-full px-3 py-2 border border-neutral-300 rounded-lg" />
         </div>
         <div className="p-4">
           <label className="text-sm text-neutral-500 block mb-2">Pulldown</label>
           <input type="text" value={cassette.pulldown || ''} onChange={(e) => updateSetting(['cassette', 'pulldown'], e.target.value)} className="w-full px-3 py-2 border border-neutral-300 rounded-lg" />
-        </div>
+        </div> */}
         <div className="p-4">
           <label className="text-sm text-neutral-500 block mb-2">URL</label>
           <input type="text" value={cassette.url || ''} onChange={(e) => updateSetting(['cassette', 'url'], e.target.value)} className="w-full px-3 py-2 border border-neutral-300 rounded-lg" />