Force soft top scroll edge effect for banner and video info views

iOS 27 changes the default scroll edge effect style to hard, which
draws a sharp cutoff line over the channel banner and video info
gradient extending under the toolbar.

Yattee/Extensions/View+SoftScrollEdgeEffect.swift

@@ -0,0 +1,24 @@
+//
+//  View+SoftScrollEdgeEffect.swift
+//  Yattee
+//
+//  iOS 27 changed the default scroll edge effect style from soft to hard,
+//  which draws a sharp dividing line under the toolbar. Views that extend
+//  a banner or gradient beneath the toolbar (channel header, video info)
+//  need the soft style so the artwork stays cleanly visible.
+//
+
+import SwiftUI
+
+extension View {
+    /// Forces the soft (blur/fade) scroll edge effect on the top edge
+    /// for scroll views in this hierarchy. No-op before iOS 26/macOS 26.
+    @ViewBuilder
+    func softTopScrollEdgeEffect() -> some View {
+        if #available(iOS 26, macOS 26, tvOS 26, *) {
+            scrollEdgeEffectStyle(.soft, for: .top)
+        } else {
+            self
+        }
+    }
+}

Yattee/Views/Channel/ChannelView.swift

@@ -368,6 +368,7 @@ struct ChannelView: View {
         }
         .background(viewBackgroundColor)
         .ignoresSafeArea(edges: .top)
+        .softTopScrollEdgeEffect()
         #if os(macOS)
         .overlay(alignment: .top) {
             legacyToolbarScrim
@@ -533,6 +534,7 @@ struct ChannelView: View {
         }
         .background(viewBackgroundColor)
         .ignoresSafeArea(edges: .top)
+        .softTopScrollEdgeEffect()
         #if os(macOS)
         .overlay(alignment: .top) {
             legacyToolbarScrim

Yattee/Views/Video/VideoInfoView.swift

@@ -545,6 +545,7 @@ struct VideoInfoView: View {
                 #if !os(tvOS)
                 .scrollDismissesKeyboard(.interactively)
                 #endif
+                .softTopScrollEdgeEffect()
                 .modifier(VideoInfoScrollOffsetModifier(scrollOffset: $scrollOffset))
 
                 #if os(macOS)