feat: Add numeric animation and smart delay for online count

Improvements to the online user count display:
1. Apply SwiftUI numericText animation when count changes (iOS 16+)
2. Add 300ms delay before hiding refresh indicator when count changes
3. Record previous count to detect changes during refresh

This creates a smoother UX by:
- Animating number transitions instead of instant changes
- Keeping the indicator visible longer when data updates
- Allowing users to see the count change before it disappears

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: graycreate

V2er/View/Widget/Updatable/HeadIndicatorView.swift

@@ -15,6 +15,8 @@ struct HeadIndicatorView: View {
     @Binding var isRefreshing: Bool
     var onlineStats: OnlineStatsInfo?
 
+    @State private var animatedOnlineCount: Int = 0
+
     var offset: CGFloat {
         return isRefreshing ? (0 - scrollY) : -height
     }
@@ -25,6 +27,9 @@ struct HeadIndicatorView: View {
         self._progress = progress
         self._isRefreshing = isRefreshing
         self.onlineStats = onlineStats
+        if let stats = onlineStats {
+            self._animatedOnlineCount = State(initialValue: stats.onlineCount)
+        }
     }
 
     var body: some View {
@@ -41,9 +46,22 @@ struct HeadIndicatorView: View {
                     Circle()
                         .fill(Color.hex(0x52bf1c))
                         .frame(width: 6, height: 6)
-                    Text("\(stats.onlineCount) 人在线")
-                        .font(.caption)
-                        .foregroundColor(.secondaryText)
+
+                    if #available(iOS 16.0, *) {
+                        Text("\(animatedOnlineCount) 人在线")
+                            .font(.caption)
+                            .foregroundColor(.secondaryText)
+                            .contentTransition(.numericText())
+                    } else {
+                        Text("\(animatedOnlineCount) 人在线")
+                            .font(.caption)
+                            .foregroundColor(.secondaryText)
+                    }
+                }
+                .onChange(of: stats.onlineCount) { newValue in
+                    withAnimation(.easeInOut(duration: 0.3)) {
+                        animatedOnlineCount = newValue
+                    }
                 }
             }
         }

V2er/View/Widget/Updatable/UpdatableView.swift

@@ -31,6 +31,7 @@ struct UpdatableView<Content: View>: View {
     @State var hapticed = false
     let state: UpdatableState
     let onlineStats: OnlineStatsInfo?
+    @State private var previousOnlineCount: Int? = nil
 
     private var refreshable: Bool {
         return onRefresh != nil
@@ -123,11 +124,30 @@ struct UpdatableView<Content: View>: View {
             && lastScrollY > threshold {
             isRefreshing = true
             hapticed = false
+            // Record current online count before refresh
+            previousOnlineCount = onlineStats?.onlineCount
+
             Task {
                 await onRefresh?()
                 runInMain {
-                    withAnimation {
-                        isRefreshing = false
+                    // Check if online count changed
+                    let currentCount = onlineStats?.onlineCount
+                    let onlineCountChanged = previousOnlineCount != nil && currentCount != nil && previousOnlineCount != currentCount
+
+                    if onlineCountChanged {
+                        // Delay hiding if online count changed
+                        Task {
+                            try? await Task.sleep(nanoseconds: 300_000_000) // 300ms
+                            runInMain {
+                                withAnimation {
+                                    isRefreshing = false
+                                }
+                            }
+                        }
+                    } else {
+                        withAnimation {
+                            isRefreshing = false
+                        }
                     }
                 }
             }