feat: add easter egg with triple-tap AppBar and animation

lib/settings_screen.dart

@@ -1,5 +1,6 @@
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
+import 'package:url_launcher/url_launcher.dart';
 import 'bridge/location_bridge.dart';
 import 'preferences.dart';
 
@@ -19,6 +20,38 @@ class _SettingsScreenState extends State<SettingsScreen> {
   late int _accuracy;
   late bool _offlineBuffer;
   late bool _stopDetection;
+  bool _showEasterEgg = false;
+  int _tapCount = 0;
+  DateTime? _lastTapTime;
+
+  void _handleAppBarTap() {
+    const tripleTapInterval = Duration(milliseconds: 500);
+    final now = DateTime.now();
+
+    if (_lastTapTime != null &&
+        now.difference(_lastTapTime!) > tripleTapInterval) {
+      _tapCount = 0;
+    }
+
+    _tapCount++;
+    _lastTapTime = now;
+
+    if (_tapCount == 3) {
+      _tapCount = 0;
+      setState(() => _showEasterEgg = true);
+    }
+  }
+
+  Future<void> _triggerEasterEgg() async {
+    await Future.delayed(const Duration(milliseconds: 1500));
+    final uri = Uri.parse('https://fiatcode.dev');
+    if (await canLaunchUrl(uri)) {
+      await launchUrl(uri, mode: LaunchMode.externalApplication);
+    }
+    if (mounted) {
+      setState(() => _showEasterEgg = false);
+    }
+  }
 
   @override
   void initState() {
@@ -116,14 +149,17 @@ class _SettingsScreenState extends State<SettingsScreen> {
           ),
           onPressed: () => Navigator.pop(context),
         ),
-        title: const Text(
+        title: GestureDetector(
-          'SETTINGS',
+          onTap: _handleAppBarTap,
-          style: TextStyle(
+          child: const Text(
-            fontFamily: 'monospace',
+            'SETTINGS',
-            fontSize: 14,
+            style: TextStyle(
-            fontWeight: FontWeight.w700,
+              fontFamily: 'monospace',
-            letterSpacing: 2,
+              fontSize: 14,
-            color: Color(0xFFe0e0e0),
+              fontWeight: FontWeight.w700,
+              letterSpacing: 2,
+              color: Color(0xFFe0e0e0),
+            ),
           ),
         ),
         bottom: PreferredSize(
@@ -168,6 +204,7 @@ class _SettingsScreenState extends State<SettingsScreen> {
           const SizedBox(height: 32),
           _buildSaveButton(),
           const SizedBox(height: 20),
+          if (_showEasterEgg) _buildEasterEggOverlay(),
         ],
       ),
     );
@@ -400,4 +437,39 @@ class _SettingsScreenState extends State<SettingsScreen> {
       ),
     );
   }
+
+  Widget _buildEasterEggOverlay() {
+    return AnimatedOpacity(
+      opacity: _showEasterEgg ? 1.0 : 0.0,
+      duration: const Duration(milliseconds: 300),
+      onEnd: _triggerEasterEgg,
+      child: AnimatedScale(
+        scale: _showEasterEgg ? 1.0 : 0.5,
+        duration: const Duration(milliseconds: 300),
+        curve: Curves.easeOutBack,
+        child: Container(
+          color: Colors.black.withValues(alpha: 0.85),
+          width: double.infinity,
+          height: double.infinity,
+          child: Center(
+            child: Text(
+              '🎉 FIAT CODE! 🎉',
+              style: TextStyle(
+                fontFamily: 'monospace',
+                fontSize: 32,
+                fontWeight: FontWeight.w700,
+                color: const Color(0xFF00e676),
+                shadows: [
+                  Shadow(
+                    color: const Color(0xFF00e676).withValues(alpha: 0.5),
+                    blurRadius: 20,
+                  ),
+                ],
+              ),
+            ),
+          ),
+        ),
+      ),
+    );
+  }
 }

pubspec.lock

@@ -485,6 +485,70 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.4.0"
+  url_launcher:
+    dependency: "direct main"
+    description:
+      name: url_launcher
+      sha256: f6a7e5c4835bb4e3026a04793a4199ca2d14c739ec378fdfe23fc8075d0439f8
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.3.2"
+  url_launcher_android:
+    dependency: transitive
+    description:
+      name: url_launcher_android
+      sha256: "3bb000251e55d4a209aa0e2e563309dc9bb2befea2295fd0cec1f51760aac572"
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.3.29"
+  url_launcher_ios:
+    dependency: transitive
+    description:
+      name: url_launcher_ios
+      sha256: "580fe5dfb51671ae38191d316e027f6b76272b026370708c2d898799750a02b0"
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.4.1"
+  url_launcher_linux:
+    dependency: transitive
+    description:
+      name: url_launcher_linux
+      sha256: d5e14138b3bc193a0f63c10a53c94b91d399df0512b1f29b94a043db7482384a
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.2.2"
+  url_launcher_macos:
+    dependency: transitive
+    description:
+      name: url_launcher_macos
+      sha256: "368adf46f71ad3c21b8f06614adb38346f193f3a59ba8fe9a2fd74133070ba18"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.2.5"
+  url_launcher_platform_interface:
+    dependency: transitive
+    description:
+      name: url_launcher_platform_interface
+      sha256: "552f8a1e663569be95a8190206a38187b531910283c3e982193e4f2733f01029"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.3.2"
+  url_launcher_web:
+    dependency: transitive
+    description:
+      name: url_launcher_web
+      sha256: d0412fcf4c6b31ecfdb7762359b7206ffba3bbffd396c6d9f9c4616ece476c1f
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.4.2"
+  url_launcher_windows:
+    dependency: transitive
+    description:
+      name: url_launcher_windows
+      sha256: "712c70ab1b99744ff066053cbe3e80c73332b38d46e5e945c98689b2e66fc15f"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.1.5"
   vector_math:
     dependency: transitive
     description: