feat: Murattal player enhancements & prayer schedule auto-scroll

- Murattal: Spotify-style 5-button controls [Shuffle, Prev, Play, Next, Playlist]
- Murattal: Animated 7-bar equalizer visualization in player circle
- Murattal: Unsplash API background with frosted glass player overlay
- Murattal: Transparent AppBar with backdrop blur
- Murattal: Surah playlist bottom sheet with full 114 Surah list
- Murattal: Auto-play disabled on screen open, enabled on navigation
- Murattal: Shuffle mode for random Surah playback
- Murattal: Photographer attribution per Unsplash guidelines
- Dashboard: Auto-scroll prayer schedule to next active prayer
- Fix: setState lifecycle errors on Reading & Murattal screens
- Setup: flutter_dotenv, cached_network_image, url_launcher deps

lib/core/widgets/bottom_nav_bar.dart

@@ -0,0 +1,66 @@
+import 'package:flutter/material.dart';
+import '../../app/theme/app_colors.dart';
+
+/// 5-tab bottom navigation bar per PRD §5.1.
+/// Uses Material Symbols outlined (inactive) and filled (active).
+class AppBottomNavBar extends StatelessWidget {
+  const AppBottomNavBar({
+    super.key,
+    required this.currentIndex,
+    required this.onTap,
+  });
+
+  final int currentIndex;
+  final ValueChanged<int> onTap;
+
+  @override
+  Widget build(BuildContext context) {
+    return Container(
+      decoration: BoxDecoration(
+        color: Theme.of(context).bottomNavigationBarTheme.backgroundColor,
+        border: Border(
+          top: BorderSide(
+            color: Theme.of(context).dividerColor,
+            width: 0.5,
+          ),
+        ),
+      ),
+      child: SafeArea(
+        child: Padding(
+          padding: const EdgeInsets.only(bottom: 8),
+          child: BottomNavigationBar(
+            currentIndex: currentIndex,
+            onTap: onTap,
+            items: const [
+              BottomNavigationBarItem(
+                icon: Icon(Icons.home_outlined),
+                activeIcon: Icon(Icons.home),
+                label: 'Beranda',
+              ),
+              BottomNavigationBarItem(
+                icon: Icon(Icons.calendar_today_outlined),
+                activeIcon: Icon(Icons.calendar_today),
+                label: 'Jadwal',
+              ),
+              BottomNavigationBarItem(
+                icon: Icon(Icons.rule_outlined),
+                activeIcon: Icon(Icons.rule),
+                label: 'Ibadah',
+              ),
+              BottomNavigationBarItem(
+                icon: Icon(Icons.bar_chart_outlined),
+                activeIcon: Icon(Icons.bar_chart),
+                label: 'Laporan',
+              ),
+              BottomNavigationBarItem(
+                icon: Icon(Icons.auto_fix_high_outlined),
+                activeIcon: Icon(Icons.auto_fix_high),
+                label: 'Alat',
+              ),
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+}