feat: offer timed opening and ending skips

Checks/cast-playback.swift

@@ -211,7 +211,7 @@ struct CastPlaybackCheck {
         let suite = "terebi.cast-playback-check." + UUID().uuidString
         let defaults = UserDefaults(suiteName: suite)!
         defer { defaults.removePersistentDomain(forName: suite) }
-        let model = PlayerModel(defaults: defaults)
+        let model = PlayerModel(defaults: defaults, skipClock: { 100 })
         defer { model.shutdown() }
         if CommandLine.arguments.count == 5 {
             if CommandLine.arguments[3] == "queue" {
@@ -249,6 +249,17 @@ struct CastPlaybackCheck {
         require(model.setPlayback(playing: false), "remote pause accepted")
         try await until(model, "receiver pause acknowledged") { model.state.status == PLAYER_PAUSED && model.playbackIntent == nil }
         requirePlaybackPower(system: false, display: false, "receiver pause permits sleep")
+        let opening = MiruroInterval(kind: .intro, start: 23, end: 24.25, episode: 1)
+        model.supplyMetadataForCheck(MiruroMetadata(title: nil, intervals: [opening]), episode: 1)
+        require(model.seekRelative(24 - model.state.position), "enter opening on receiver")
+        try await until(model, "receiver offers opening only after acknowledging seek") {
+            !model.state.seek_pending && model.segmentToSkip == opening
+        }
+        require(model.skipSegment(), "segment skip queues receiver seek")
+        try await until(model, "receiver acknowledges segment end without starting playback") {
+            !model.state.seek_pending && abs(model.state.position - 24.25) < 0.15 &&
+                model.state.status == PLAYER_PAUSED && model.segmentToSkip == nil
+        }
         model.stopCasting()
         try await until(model, "local decoder restores receiver position paused") {
             model.castDevice == nil && model.state.status == PLAYER_PAUSED && !model.state.seek_pending &&