fix: title bar shows/hides based on window hover, not just top strip

- Remove 28pt overlay hover detection
- Add .onHover to entire window content (ZStack)
- Extract setWindowTitleBarVisible() helper function
- Mouse enters window → show title bar, mouse leaves → hide

Sources/MiniPlayerApp.swift

@@ -241,6 +241,15 @@ struct PlayerContentView: View {
         }
     }
     
+    private func setWindowTitleBarVisible(_ visible: Bool) {
+        guard let win = NSApplication.shared.windows.first(where: { $0.isVisible }) else { return }
+        win.titlebarAppearsTransparent = !visible
+        win.titleVisibility = visible ? .visible : .hidden
+        win.standardWindowButton(.closeButton)?.isHidden = !visible
+        win.standardWindowButton(.miniaturizeButton)?.isHidden = !visible
+        win.standardWindowButton(.zoomButton)?.isHidden = !visible
+    }
+    
     var body: some View {
         ZStack(alignment: .topLeading) {
             Color.black.ignoresSafeArea()
@@ -318,6 +327,9 @@ struct PlayerContentView: View {
                 }
             }
         }
+        .onHover { hovering in
+            setWindowTitleBarVisible(hovering)
+        }
         .onAppear {
             // 初始状态：标题栏完全隐藏（含红绿灯按钮）
             DispatchQueue.main.asyncAfter(deadline: .now() + 0.1) {
@@ -337,28 +349,6 @@ struct PlayerContentView: View {
                 hideTimer?.invalidate()
             }
         }
-        .overlay(alignment: .top) {
-            // 标题栏悬停检测：鼠标进入显示标题栏，退出隐藏
-            Color.clear
-                .frame(height: 28)
-                .contentShape(Rectangle())
-                .onHover { hovering in
-                    guard let win = NSApplication.shared.windows.first(where: { $0.isVisible }) else { return }
-                    if hovering {
-                        win.titlebarAppearsTransparent = false
-                        win.titleVisibility = .visible
-                        win.standardWindowButton(.closeButton)?.isHidden = false
-                        win.standardWindowButton(.miniaturizeButton)?.isHidden = false
-                        win.standardWindowButton(.zoomButton)?.isHidden = false
-                    } else {
-                        win.titleVisibility = .hidden
-                        win.titlebarAppearsTransparent = true
-                        win.standardWindowButton(.closeButton)?.isHidden = true
-                        win.standardWindowButton(.miniaturizeButton)?.isHidden = true
-                        win.standardWindowButton(.zoomButton)?.isHidden = true
-                    }
-                }
-        }
         .onDisappear {
             hideTimer?.invalidate()
         }