Player: a sleep timer, and AirPlay in the app (#429)

The sleep timer pauses after 5 minutes to an hour, fading out over the
last ten seconds. In the iOS app the phone's player keeps the time:
with the screen locked the web view is frozen, and a timer in the page
would not fire until the app was opened again. A browser plays on in a
background tab, so there the page keeps it.

The app says at ready what it does itself ({t:"host", can}), so a page
deployed ahead of the app falls back to its own timer and shows no
AirPlay button an older app would ignore. This deploy order problem
came up with #425.

AirPlay opens AVRoutePickerView by pressing its button from code; there
is no API to present it. On iOS 27 the picker opens on the button's
primary action, not touch-up, so that is what is sent, with touch-up
for versions that have nothing on it. The simulator has no AirPlay
devices and never showed the picker, so this is unverified until it
runs on a phone.

On a phone the player's one line left the title two letters wide once
the two controls were added, so the title takes the top line and the
controls flank play below it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

ios/Sources/Bridge.swift

@@ -1,3 +1,4 @@
+import AVKit
 import Foundation
 import WebKit
 
@@ -13,6 +14,16 @@ final class Bridge: NSObject, WKScriptMessageHandler {
 
     private weak var webView: WKWebView?
     private let playback: Playback
+    /// The system's AirPlay picker, which has no API to open it but its own button: kept on the
+    /// web view, invisible, and pressed when the page's button is.
+    private lazy var routePicker: AVRoutePickerView = {
+        let v = AVRoutePickerView()
+        v.alpha = 0
+        v.isUserInteractionEnabled = false
+        v.prioritizesVideoDevices = false
+        webView?.addSubview(v)
+        return v
+    }()
 
     init(webView: WKWebView, playback: Playback) {
         self.webView = webView
@@ -29,6 +40,7 @@ final class Bridge: NSObject, WKScriptMessageHandler {
         playback.onState = { [weak self] playing in self?.send(["t": "state", "playing": playing]) }
         playback.onEnded = { [weak self] in self?.send(["t": "ended"]) }
         playback.onError = { [weak self] msg in self?.send(["t": "error", "message": msg]) }
+        playback.onSlept = { [weak self] in self?.send(["t": "slept"]) }
         Offline.shared.onChange = { [weak self] in self?.sendKept() }
         Offline.shared.onFail = { [weak self] path, msg in
             self?.send(["t": "keepFailed", "url": path, "message": msg])
@@ -50,6 +62,10 @@ final class Bridge: NSObject, WKScriptMessageHandler {
         case "ready":
             if let r = m["rate"] as? Double { playback.setRate(Float(r)) }
             if let v = m["volume"] as? Double { playback.setVolume(Float(v)) }
+            // What this build can do, so a newer page offers nothing it would ask for in vain.
+            send(["t": "host", "can": ["sleep", "route"]])
+            // A page reloaded while the timer runs is told how long is left.
+            if let at = playback.sleepAt { send(["t": "sleep", "left": max(0, at.timeIntervalSinceNow)]) }
             sendKept()
         case "load":
             guard let path = m["url"] as? String, let url = Server.resolveForPlayer(path),
@@ -73,10 +89,31 @@ final class Bridge: NSObject, WKScriptMessageHandler {
         case "keep": if let url = m["url"] as? String { Offline.shared.keep(url) }
         case "unkeep": if let url = m["url"] as? String { Offline.shared.remove(url) }
         case "clearKept": Offline.shared.removeAll()
+        case "sleep": playback.sleep(after: m["secs"] as? Double ?? 0)
+        case "route": showRoutes(m)
         default: break
         }
     }
 
+    /// Opens the picker over the page's button: on an iPhone a sheet, on an iPad a popover
+    /// pointing at it. The page sends where the button is, in the web view's points.
+    private func showRoutes(_ m: [String: Any]) {
+        let n = { (k: String) in m[k] as? Double ?? 0 }
+        routePicker.frame = CGRect(x: n("x"), y: n("y"), width: max(1, n("w")), height: max(1, n("h")))
+        // Its button is made on layout, and opens the picker on its primary action; a version
+        // with nothing on that, as older ones may have, gets the touch that used to do it.
+        routePicker.layoutIfNeeded()
+        guard let button = Self.controls(in: routePicker).first else { return }
+        let primary = button.allTargets.contains {
+            button.actions(forTarget: $0, forControlEvent: .primaryActionTriggered)?.isEmpty == false
+        }
+        button.sendActions(for: primary ? .primaryActionTriggered : .touchUpInside)
+    }
+
+    private static func controls(in v: UIView) -> [UIControl] {
+        v.subviews.flatMap { ($0 as? UIControl).map { [$0] } ?? controls(in: $0) }
+    }
+
     // MARK: - host to page
 
     private func send(_ payload: [String: Any]) {