fix: track hover across the entire player to prevent overlay feedback flicker

Checks/app-startup.swift

@@ -1,4 +1,5 @@
 import AppKit
+import Combine
 import Darwin
 import MediaPlayer
 import ObjectiveC
@@ -6,6 +7,10 @@ import ObjectiveC
 @_cdecl("terebi_app_main")
 @MainActor
 public func checkAppStartup() {
+    if let index = CommandLine.arguments.firstIndex(of: "--check-overlay-hover") {
+        OverlayHoverCheck.run(result: URL(fileURLWithPath: CommandLine.arguments[index + 1]))
+        return
+    }
     if let index = CommandLine.arguments.firstIndex(of: "--check-window-drag") {
         WindowDragCheck.run(result: URL(fileURLWithPath: CommandLine.arguments[index + 1]))
         return
@@ -25,6 +30,88 @@ public func checkAppStartup() {
     AppStartupCheck.run()
 }
 
+@MainActor
+private enum OverlayHoverCheck {
+    static var timer: Timer?
+    static var observation: AnyCancellable?
+    static var resultURL: URL!
+    static var step = 0
+    static var sample = 0
+    static var hidden = 0
+    static var savedPointer = NSPoint.zero
+    static let names = ["video", "title", "playback controls", "top-right controls",
+                        "queue controls", "window exit", "window reentry"]
+    // Infrastructure watchdog only; verdicts use native hover events and visibility changes.
+    static let deadline = ContinuousClock.now.advanced(by: .seconds(20))
+
+    static func run(result: URL) {
+        resultURL = result
+        _ = NSApplication.shared
+        savedPointer = NSEvent.mouseLocation
+        timer = Timer.scheduledTimer(withTimeInterval: 0.05, repeats: true) { _ in
+            MainActor.assumeIsolated { advance() }
+        }
+        terebiAppMain()
+    }
+
+    static func finish(_ error: String = "") {
+        timer?.invalidate()
+        observation = nil
+        CGWarpMouseCursorPosition(CGPoint(x: savedPointer.x, y: NSScreen.screens[0].frame.maxY - savedPointer.y))
+        let report: [String: Any] = ["passed": error.isEmpty, "error": error, "steps": step]
+        try! JSONSerialization.data(withJSONObject: report).write(to: resultURL, options: .atomic)
+        PlayerModel.shared.shutdown()
+        NSApp.terminate(nil)
+    }
+
+    static func advance() {
+        guard ContinuousClock.now < deadline else { finish("Overlay hover timed out"); return }
+        let model = PlayerModel.shared
+        guard model.canTogglePlayback, model.state.has_video,
+              let window = NSApp.windows.first(where: { $0.canBecomeMain && !($0 is NSPanel) }),
+              let content = window.contentView else { return }
+        if observation == nil {
+            model.setVolume(0)
+            model.setPlayback(playing: false)
+            window.makeKeyAndOrderFront(nil)
+            window.makeMain()
+            NSApp.activate(ignoringOtherApps: true)
+            observation = model.$controlsVisible.removeDuplicates().dropFirst().sink { visible in
+                if !visible { hidden += 1 }
+            }
+        }
+        if step == names.count { finish(); return }
+        if step == 4 && !model.showsQueue { model.showsQueue = true; return }
+        guard !model.isQueueTransitioning else { return }
+        if sample == 0 {
+            let w = content.bounds.width
+            let h = content.bounds.height
+            let points = [NSPoint(x: w / 2, y: h / 2), NSPoint(x: 150, y: h - 16),
+                          NSPoint(x: w / 2, y: 64), NSPoint(x: w - 46, y: h - 16),
+                          NSPoint(x: w - 46, y: h - 16), NSPoint(x: -20, y: h / 2),
+                          NSPoint(x: w - 46, y: h - 16)]
+            hidden = 0
+            let screen = window.convertPoint(toScreen: points[step])
+            CGWarpMouseCursorPosition(CGPoint(x: screen.x, y: NSScreen.screens[0].frame.maxY - screen.y))
+            let event = NSEvent.mouseEvent(with: .mouseMoved, location: points[step], modifierFlags: [],
+                timestamp: 0, windowNumber: window.windowNumber, context: nil,
+                eventNumber: step, clickCount: 0, pressure: 0)!
+            NSApp.postEvent(NSEvent(cgEvent: event.cgEvent!)!, atStart: false)
+        }
+        // Let native tracking and SwiftUI updates settle; no auto-hide timer is under test.
+        sample += 1
+        if sample == 20 {
+            let outside = step == 5
+            guard model.controlsVisible != outside, outside || hidden == 0 else {
+                finish("\(names[step]): visible=\(model.controlsVisible), hidden transitions=\(hidden)")
+                return
+            }
+            sample = 0
+            step += 1
+        }
+    }
+}
+
 @MainActor
 private enum WindowDragCheck {
     static var timer: Timer?