fix: persist SponsorBlock preference between launches

Checks/resolved-playback.swift

@@ -30,6 +30,8 @@ struct ResolvedPlaybackCheck {
         }
         _ = NSApplication.shared
         NSApp.setActivationPolicy(.prohibited)
+        sponsorPreferenceCheck()
+        if CommandLine.arguments[1] == "--sponsor-preference" { return }
         let input = CommandLine.arguments[1]
         let file = URL(fileURLWithPath: input)
         let preference = CommandLine.arguments.first(where: { $0.hasPrefix("--provider=") }).map { String($0.dropFirst(11)) } ?? ""
@@ -128,6 +130,31 @@ struct ResolvedPlaybackCheck {
         }
     }
 
+    static func sponsorPreferenceCheck() {
+        let suite = "terebi.sponsor-preference." + UUID().uuidString
+        let defaults = UserDefaults(suiteName: suite)!
+        defer { defaults.removePersistentDomain(forName: suite) }
+        func launch(_ configured: Bool = false) -> PlayerModel {
+            PlayerModel(defaults: UserDefaults(suiteName: suite)!, configuration: .init(sponsorBlock: configured))
+        }
+        let first = launch()
+        require(!first.sponsorBlockEnabled, "unconfigured SponsorBlock defaults to disabled")
+        first.setSponsorBlockEnabled(true)
+        first.shutdown()
+        let second = launch()
+        require(second.sponsorBlockEnabled, "enabled preference survives a fresh model/defaults instance")
+        second.setSponsorBlockEnabled(false)
+        second.shutdown()
+        let third = launch(true)
+        require(!third.sponsorBlockEnabled, "saved disabled preference survives restart and overrides config")
+        third.shutdown()
+        defaults.removePersistentDomain(forName: suite)
+        let configured = launch(true)
+        require(configured.sponsorBlockEnabled, "config supplies the initial choice without a saved preference")
+        configured.shutdown()
+        print("PASS: SponsorBlock preference persists enable/disable across launches, with config fallback")
+    }
+
     static var fixtureSponsors: [SponsorSegment] {
         [.init(start: 0.5, end: 1.5, videoDuration: 0)]
     }