feat: settings screen, haptic toggle, rain/lightning toggles, review docs

lib/screens/settings/in_settings/rain.dart

@@ -0,0 +1,58 @@
+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.
+//
+// Same architecture as haptic.dart: exports a top-level bool read synchronously
+// by lib/components/rain.dart. Default: true (rain is on — opt-out).
+
+// lib/components/rain.dart reads this in its build method.
+bool rainEnabled = true;
+
+class RainToggleTile extends StatefulWidget {
+  const RainToggleTile({super.key});
+
+  @override
+  State<RainToggleTile> createState() => _RainToggleTileState();
+}
+
+class _RainToggleTileState extends State<RainToggleTile> {
+  bool _on = true;
+
+  @override
+  void initState() {
+    super.initState();
+    _load();
+  }
+
+  Future<void> _load() async {
+    final prefs = await SharedPreferences.getInstance();
+    final value = prefs.getBool('rain_effect_enabled') ?? true;
+    rainEnabled = value;
+    if (mounted) setState(() => _on = value);
+  }
+
+  Future<void> _toggle(bool value) async {
+    final prefs = await SharedPreferences.getInstance();
+    await prefs.setBool('rain_effect_enabled', value);
+    rainEnabled = value;
+    setState(() => _on = value);
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return SwitchListTile(
+      title: const Text(
+        'Rain effect',
+        style: TextStyle(color: AppColors.textWhite, fontSize: 15),
+      ),
+      value: _on,
+      onChanged: _toggle,
+      activeTrackColor: AppColors.accent.withAlpha(80),
+      activeThumbColor: AppColors.accent,
+      contentPadding: const EdgeInsets.symmetric(horizontal: 20, vertical: 4),
+    );
+  }
+}