Fix Slider assertion error when skipping past video duration

Prevent an AssertionError in the Slider widget when the skip duration
button causes the value to exceed the video's maximum duration.
Clamp the Slider's value to the range [0, max]
using `clamp(0.0, maxValue).toDouble()` to ensure it stays within bounds.

Exception example:
```
Exception has occurred.
_AssertionError ('package:flutter/src/material/slider.dart': Failed assertion: line 199 pos 10: 'value >= min && value <= max': Value 1410000.0 is not between minimum 0.0 and maximum 1409533.0)
```

lib/modules/anime/widgets/custom_seekbar.dart

@@ -61,6 +61,10 @@ class CustomSeekBarState extends State<CustomSeekBar> {
   final isDesktop = Platform.isMacOS || Platform.isWindows || Platform.isLinux;
   @override
   Widget build(BuildContext context) {
+    final maxValue = max(duration.inMilliseconds.toDouble(), 0).toDouble();
+    final rawValue =
+        (widget.delta ?? tempPosition ?? position).inMilliseconds.toDouble();
+    final clampedValue = rawValue.clamp(0, maxValue).toDouble();
     return SizedBox(
       height: 20,
       child: Row(
@@ -88,12 +92,8 @@ class CustomSeekBarState extends State<CustomSeekBar> {
                 overlayShape: const RoundSliderOverlayShape(overlayRadius: 5.0),
               ),
               child: Slider(
-                max: max(duration.inMilliseconds.toDouble(), 0),
-                value: max(
-                  (widget.delta ?? tempPosition ?? position).inMilliseconds
-                      .toDouble(),
-                  0,
-                ),
+                max: maxValue,
+                value: clampedValue,
                 secondaryTrackValue: max(buffer.inMilliseconds.toDouble(), 0),
                 onChanged: (value) {
                   widget.onSeekStart?.call(