iOS: presses are felt (#430)

The page asks the app for a haptic ({t:"haptic", kind}) and the app
plays the phone's own. A light tap for play, pause, flag and pull to
refresh; the system's success for marking read, one item or all; its
warning with an error toast. A browser has no host to ask, and an
older app ignores the message, so there is nothing to gate.

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

ios/Sources/Bridge.swift

@@ -14,6 +14,8 @@ final class Bridge: NSObject, WKScriptMessageHandler {
 
     private weak var webView: WKWebView?
     private let playback: Playback
+    private let impact = UIImpactFeedbackGenerator(style: .light)
+    private let notice = UINotificationFeedbackGenerator()
     /// 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 = {
@@ -91,6 +93,7 @@ final class Bridge: NSObject, WKScriptMessageHandler {
         case "clearKept": Offline.shared.removeAll()
         case "sleep": playback.sleep(after: m["secs"] as? Double ?? 0)
         case "route": showRoutes(m)
+        case "haptic": haptic(m["kind"] as? String)
         default: break
         }
     }
@@ -110,6 +113,16 @@ final class Bridge: NSObject, WKScriptMessageHandler {
         button.sendActions(for: primary ? .primaryActionTriggered : .touchUpInside)
     }
 
+    /// The page's presses felt (#430): light for a tap, the system's success and warning for
+    /// something done and something gone wrong, as Mail and Messages use them.
+    private func haptic(_ kind: String?) {
+        switch kind {
+        case "done": notice.notificationOccurred(.success)
+        case "warn": notice.notificationOccurred(.warning)
+        default: impact.impactOccurred()
+        }
+    }
+
     private static func controls(in v: UIView) -> [UIControl] {
         v.subviews.flatMap { ($0 as? UIControl).map { [$0] } ?? controls(in: $0) }
     }