refactor(app): remove unsupported runtime and UI state

lib/screens/settings/in_settings/background_reliability.dart

@@ -2,12 +2,9 @@ import 'package:flutter/material.dart';
 import 'package:revoltvpn/logic/app_colors.dart';
 import 'package:revoltvpn/logic/power_settings.dart';
 
-/// Keeping the tunnel alive is an OS concern, not an app one.
-///
-/// Android stops background services of apps that are not exempt from Doze, and
-/// removes the whole process group when its task is swiped away. There are
-/// exactly two sanctioned ways around that, both requiring one user tap, and
-/// neither can be enabled programmatically. This tile surfaces both.
+/// Android may restrict background work when battery optimisation is active.
+/// Surface the OS setting we can actually detect and request; do not promise
+/// reboot/Always-on restoration that the per-session runtime cannot guarantee.
 class BackgroundReliabilityTile extends StatefulWidget {
   const BackgroundReliabilityTile({super.key});
 
@@ -35,8 +32,6 @@ class _BackgroundReliabilityTileState extends State<BackgroundReliabilityTile>
 
   @override
   void didChangeAppLifecycleState(AppLifecycleState state) {
-    // The exemption is granted in a system dialog, so the only reliable moment
-    // to re-read it is when we come back to the foreground.
     if (state == AppLifecycleState.resumed) _refresh();
   }
 
@@ -68,8 +63,8 @@ class _BackgroundReliabilityTileState extends State<BackgroundReliabilityTile>
             style: TextStyle(color: AppColors.textWhite, fontSize: 15),
           ),
           subtitle: Text(
-            'Android stops background apps to save power. Disabling battery '
-            'optimisation is what keeps the VPN running when the app is closed.',
+            'Android may restrict background work to save power. ReVolt only '
+            'shows the system control it can verify.',
             style: TextStyle(color: AppColors.textDim, fontSize: 12),
           ),
         ),
@@ -83,8 +78,8 @@ class _BackgroundReliabilityTileState extends State<BackgroundReliabilityTile>
                     ? 'Battery optimisation: checking…'
                     : exempt
                         ? 'Battery optimisation: disabled for Revolt VPN ✓'
-                        : 'Battery optimisation: still active — the system may '
-                            'stop the VPN in the background.',
+                        : 'Battery optimisation: active — Android may stop '
+                            'background VPN work.',
                 style: TextStyle(
                   color: exempt == true ? AppColors.accent : AppColors.textMuted,
                   fontSize: 12,

lib/screens/settings/in_settings/connection_mode.dart

@@ -51,8 +51,14 @@ class _ConnectionModeTileState extends State<ConnectionModeTile> {
       return;
     }
 
-    await ConnectionSettings.setMode(next);
+    final saved = await ConnectionSettings.setMode(next);
     if (!mounted) return;
+    if (!saved) {
+      ScaffoldMessenger.of(context).showSnackBar(
+        const SnackBar(content: Text('Could not save connection mode.')),
+      );
+      return;
+    }
 
     setState(() {
       _mode = next;
@@ -61,10 +67,6 @@ class _ConnectionModeTileState extends State<ConnectionModeTile> {
     widget.onChanged?.call(next);
   }
 
-  /// Recovers from an orphaned proxy: tear the runtime down and start a fresh
-  /// session so a readable set of credentials exists again. No rewarded ad —
-  /// the user is repairing a connection they already paid for, not opening a
-  /// new one.
   Future<void> _reconnect() async {
     if (_reconnecting) return;
     final vpn = context.read<VpnConnection>();
@@ -168,11 +170,6 @@ class _ConnectionModeTileState extends State<ConnectionModeTile> {
             builder: (context, vpn, _) {
               final session = vpn.activeSocksSession;
               if (session == null) {
-                // The proxy can be running while this session is unknown:
-                // Android killed the app process, the foreground service kept
-                // the listener alive, and its credentials existed only in the
-                // memory that died with it. Saying "Connect" there would be a
-                // lie — the user is already connected.
                 final orphaned = vpn.status == VpnStatus.connected &&
                     vpn.adoptedRunningRuntime;
                 if (orphaned) {

lib/screens/settings/in_settings/lightning.dart

@@ -2,9 +2,6 @@ import 'package:flutter/material.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 import 'package:revoltvpn/logic/app_colors.dart';
 
-// ── lib/screens/settings/in_settings/lightning.dart ─────────────────────────
-// Toggle for the lightning strike overlay on the main screen.
-
 final ValueNotifier<bool> lightningEnabled = ValueNotifier(true);
 
 Future<void> loadLightningPref() async {
@@ -35,7 +32,9 @@ class _LightningToggleTileState extends State<LightningToggleTile> {
 
   Future<void> _toggle(bool value) async {
     final prefs = await SharedPreferences.getInstance();
-    await prefs.setBool('lightning_effect_enabled', value);
+    final saved = await prefs.setBool('lightning_effect_enabled', value);
+    if (!saved || !mounted) return;
+
     lightningEnabled.value = value;
     setState(() => _on = value);
   }

lib/screens/settings/in_settings/rain.dart

@@ -2,9 +2,6 @@ import 'package:flutter/material.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 import 'package:revoltvpn/logic/app_colors.dart';
 
-// ── lib/screens/settings/in_settings/rain.dart ──────────────────────────────
-// Toggle for the animated rain overlay on the main screen.
-
 final ValueNotifier<bool> rainEnabled = ValueNotifier(true);
 
 Future<void> loadRainPref() async {
@@ -35,7 +32,9 @@ class _RainToggleTileState extends State<RainToggleTile> {
 
   Future<void> _toggle(bool value) async {
     final prefs = await SharedPreferences.getInstance();
-    await prefs.setBool('rain_effect_enabled', value);
+    final saved = await prefs.setBool('rain_effect_enabled', value);
+    if (!saved || !mounted) return;
+
     rainEnabled.value = value;
     setState(() => _on = value);
   }