feature: built-in auto-update (appcast + sha256 + staged install), version 0.2.0

Info.plist

@@ -15,7 +15,7 @@
 	<key>CFBundlePackageType</key>
 	<string>APPL</string>
 	<key>CFBundleShortVersionString</key>
-	<string>0.1.0</string>
+	<string>0.2.0</string>
 	<key>CFBundleVersion</key>
 	<string>1</string>
 	<key>CFBundleIconFile</key>

Sources/Shotdeck/AppModel.swift

@@ -1,5 +1,4 @@
 import AppKit
-import Carbon.HIToolbox
 import Foundation
 import Observation
 import SwiftUI
@@ -37,6 +36,11 @@ public final class AppModel {
     public private(set) var outboxURL: URL
     /// Live watch folder; WP-4c updates this alongside `ReturnWatcher.updateWatchFolder`.
     public private(set) var watchFolderURL: URL
+    /// Currently bound capture combo (the last one Carbon accepted, or the preferred load).
+    private(set) var captureHotkey: HotkeyPreference
+    var hotkeyDisplayString: String { captureHotkey.displayString }
+    /// Staged update offered in the menu. Set only after checksum + payload validation.
+    public private(set) var updateAvailable: (version: String, notes: String)?
 
     let paths: AppSupportPaths
     let spool: SpoolStore
@@ -46,6 +50,7 @@ public final class AppModel {
     let picker: RegionPickerController
     let ledger: ReturnLedger
     let watcher: ReturnWatcher
+    let updateChecker: UpdateChecker
 
     public init(
         paths: AppSupportPaths,
@@ -80,6 +85,15 @@ public final class AppModel {
         self.watchFolderURL = folders.watch
         self.outboxDisplayName = folders.outbox.lastPathComponent
         self.watchFolderDisplayName = folders.watch.lastPathComponent
+        self.captureHotkey = HotkeyPreference.load()
+        self.updateChecker = UpdateChecker()
+        self.updateChecker.onChecked = { [weak self] in
+            guard let self else { return }
+            self.updateAvailable = self.updateChecker.availableUpdate
+            if let message = self.updateChecker.statusMessage {
+                self.setStatus(message)
+            }
+        }
     }
 
     // MARK: Seam mutators — the only way a WP-4b/4c extension changes state.
@@ -146,16 +160,53 @@ public final class AppModel {
             setStatus((error as? ShotdeckError)?.errorDescription ?? "Could not watch the return folder.")
         }
 
-        let registered = hotkeys.register(
+        let pref = HotkeyPreference.load()
+        captureHotkey = pref
+        if !bindCaptureHotkey(pref) {
+            setStatus("\(pref.displayString) is already used by another app — capture only works from the menu.")
+        }
+
+        let skipSchedule =
+            ProcessInfo.processInfo.environment["SHOTDECK_PICKER_SELFTEST"] != nil
+            || ProcessInfo.processInfo.environment["SHOTDECK_SNAPSHOT_DIR"] != nil
+            || ProcessInfo.processInfo.environment["SHOTDECK_UPDATE_SELFTEST"] != nil
+        if !skipSchedule {
+            updateChecker.startSchedule()
+        }
+    }
+
+    /// Installs the staged update over `/Applications/Redline.app` and relaunches.
+    /// Does nothing unless the user clicked the menu row.
+    public func installUpdate() {
+        updateChecker.installStaged()
+    }
+
+    /// Unregisters `capture` and binds `HotkeyPreference.load()`. If Carbon rejects the new
+    /// combo, restores the previous preference (UserDefaults + Carbon) so the old one keeps working.
+    func reRegisterHotkey() {
+        let previous = captureHotkey
+        let next = HotkeyPreference.load()
+        hotkeys.unregister(id: "capture")
+        if bindCaptureHotkey(next) {
+            captureHotkey = next
+            return
+        }
+        setStatus("That combination is taken — pick another.")
+        previous.save()
+        if bindCaptureHotkey(previous) {
+            captureHotkey = previous
+        }
+    }
+
+    @discardableResult
+    private func bindCaptureHotkey(_ pref: HotkeyPreference) -> Bool {
+        hotkeys.register(
             id: "capture",
-            keyCode: UInt32(kVK_ANSI_2),
+            keyCode: pref.keyCode,
-            modifiers: UInt32(optionKey | shiftKey)
+            modifiers: pref.modifiers
         ) { [weak self] in
             Task { await self?.captureNow() }
         }
-        if !registered {
-            setStatus("⌥⇧2 is already used by another app — capture only works from the menu.")
-        }
     }
 
     public func captureNow() async {

Sources/Shotdeck/HotkeyPreference.swift

@@ -0,0 +1,151 @@
+import AppKit
+import Carbon.HIToolbox
+import Foundation
+
+/// User-chosen capture hotkey. `modifiers` are Carbon bits (`cmdKey`, `optionKey`,
+/// `shiftKey`, `controlKey`), matching `HotkeyCenter.register`.
+struct HotkeyPreference: Codable, Equatable, Sendable {
+    var keyCode: UInt32
+    var modifiers: UInt32
+
+    static let defaultsKey = "ai.flowmaster.shotdeck.hotkey"
+
+    /// ⌥⇧2 — kVK_ANSI_2 (19) with optionKey|shiftKey.
+    static let `default` = HotkeyPreference(
+        keyCode: 19,
+        modifiers: UInt32(optionKey) | UInt32(shiftKey)
+    )
+
+    static func load(defaults: UserDefaults = .standard) -> HotkeyPreference {
+        guard let data = defaults.data(forKey: defaultsKey),
+              let decoded = try? JSONDecoder().decode(HotkeyPreference.self, from: data),
+              decoded.modifiers != 0
+        else { return .default }
+        return decoded
+    }
+
+    func save(defaults: UserDefaults = .standard) {
+        guard let data = try? JSONEncoder().encode(self) else { return }
+        defaults.set(data, forKey: Self.defaultsKey)
+    }
+
+    /// ⌘⌥⇧⌃ in that order, then a name for common keycodes.
+    var displayString: String {
+        var s = ""
+        if modifiers & UInt32(cmdKey) != 0 { s += "⌘" }
+        if modifiers & UInt32(optionKey) != 0 { s += "⌥" }
+        if modifiers & UInt32(shiftKey) != 0 { s += "⇧" }
+        if modifiers & UInt32(controlKey) != 0 { s += "⌃" }
+        s += Self.keyName(for: keyCode)
+        return s
+    }
+
+    /// `nil` when the event is modifier-only or has no ⌘⌥⇧⌃ flags.
+    static func fromKeyEvent(keyCode: UInt16, modifierFlags: NSEvent.ModifierFlags) -> HotkeyPreference? {
+        switch Int(keyCode) {
+        case kVK_Shift, kVK_RightShift,
+             kVK_Command, kVK_RightCommand,
+             kVK_Option, kVK_RightOption,
+             kVK_Control, kVK_RightControl,
+             kVK_CapsLock, kVK_Function:
+            return nil
+        default:
+            break
+        }
+        var carbon: UInt32 = 0
+        if modifierFlags.contains(.command) { carbon |= UInt32(cmdKey) }
+        if modifierFlags.contains(.option) { carbon |= UInt32(optionKey) }
+        if modifierFlags.contains(.shift) { carbon |= UInt32(shiftKey) }
+        if modifierFlags.contains(.control) { carbon |= UInt32(controlKey) }
+        guard carbon != 0 else { return nil }
+        return HotkeyPreference(keyCode: UInt32(keyCode), modifiers: carbon)
+    }
+
+    private static func keyName(for keyCode: UInt32) -> String {
+        switch Int(keyCode) {
+        case kVK_ANSI_A: return "A"
+        case kVK_ANSI_B: return "B"
+        case kVK_ANSI_C: return "C"
+        case kVK_ANSI_D: return "D"
+        case kVK_ANSI_E: return "E"
+        case kVK_ANSI_F: return "F"
+        case kVK_ANSI_G: return "G"
+        case kVK_ANSI_H: return "H"
+        case kVK_ANSI_I: return "I"
+        case kVK_ANSI_J: return "J"
+        case kVK_ANSI_K: return "K"
+        case kVK_ANSI_L: return "L"
+        case kVK_ANSI_M: return "M"
+        case kVK_ANSI_N: return "N"
+        case kVK_ANSI_O: return "O"
+        case kVK_ANSI_P: return "P"
+        case kVK_ANSI_Q: return "Q"
+        case kVK_ANSI_R: return "R"
+        case kVK_ANSI_S: return "S"
+        case kVK_ANSI_T: return "T"
+        case kVK_ANSI_U: return "U"
+        case kVK_ANSI_V: return "V"
+        case kVK_ANSI_W: return "W"
+        case kVK_ANSI_X: return "X"
+        case kVK_ANSI_Y: return "Y"
+        case kVK_ANSI_Z: return "Z"
+        case kVK_ANSI_0: return "0"
+        case kVK_ANSI_1: return "1"
+        case kVK_ANSI_2: return "2"
+        case kVK_ANSI_3: return "3"
+        case kVK_ANSI_4: return "4"
+        case kVK_ANSI_5: return "5"
+        case kVK_ANSI_6: return "6"
+        case kVK_ANSI_7: return "7"
+        case kVK_ANSI_8: return "8"
+        case kVK_ANSI_9: return "9"
+        case kVK_ANSI_Equal: return "="
+        case kVK_ANSI_Minus: return "-"
+        case kVK_ANSI_RightBracket: return "]"
+        case kVK_ANSI_LeftBracket: return "["
+        case kVK_ANSI_Quote: return "'"
+        case kVK_ANSI_Semicolon: return ";"
+        case kVK_ANSI_Backslash: return "\\"
+        case kVK_ANSI_Comma: return ","
+        case kVK_ANSI_Slash: return "/"
+        case kVK_ANSI_Period: return "."
+        case kVK_ANSI_Grave: return "`"
+        case kVK_Space: return "Space"
+        case kVK_Return: return "Return"
+        case kVK_Tab: return "Tab"
+        case kVK_Delete: return "Delete"
+        case kVK_ForwardDelete: return "Fwd Delete"
+        case kVK_Escape: return "Esc"
+        case kVK_Home: return "Home"
+        case kVK_End: return "End"
+        case kVK_PageUp: return "Page Up"
+        case kVK_PageDown: return "Page Down"
+        case kVK_Help: return "Help"
+        case kVK_LeftArrow: return "←"
+        case kVK_RightArrow: return "→"
+        case kVK_DownArrow: return "↓"
+        case kVK_UpArrow: return "↑"
+        case kVK_F1: return "F1"
+        case kVK_F2: return "F2"
+        case kVK_F3: return "F3"
+        case kVK_F4: return "F4"
+        case kVK_F5: return "F5"
+        case kVK_F6: return "F6"
+        case kVK_F7: return "F7"
+        case kVK_F8: return "F8"
+        case kVK_F9: return "F9"
+        case kVK_F10: return "F10"
+        case kVK_F11: return "F11"
+        case kVK_F12: return "F12"
+        case kVK_F13: return "F13"
+        case kVK_F14: return "F14"
+        case kVK_F15: return "F15"
+        case kVK_F16: return "F16"
+        case kVK_F17: return "F17"
+        case kVK_F18: return "F18"
+        case kVK_F19: return "F19"
+        case kVK_F20: return "F20"
+        default: return "Key \(keyCode)"
+        }
+    }
+}

Sources/Shotdeck/MenuBarView.swift

@@ -49,7 +49,7 @@ struct MenuBarView: View {
 
     private var defaultStatusText: String {
         guard let region = model.region else {
-            return "No region yet — press ⌥⇧2 to pick one."
+            return "No region yet — press \(model.hotkeyDisplayString) to pick one."
         }
         let w = Int(region.rect.width)
         let h = Int(region.rect.height)
@@ -74,6 +74,15 @@ struct MenuBarView: View {
 
     private var actionsList: some View {
         VStack(alignment: .leading, spacing: 2) {
+            if let update = model.updateAvailable {
+                Button {
+                    model.installUpdate()
+                } label: {
+                    actionLabel("Update to \(update.version)")
+                        .foregroundStyle(Color.accentColor)
+                }
+            }
+
             Button {
                 let anchor = NSApp.keyWindow?.contentView
                 if let sender = model as? SendCapable {
@@ -89,7 +98,7 @@ struct MenuBarView: View {
             Button {
                 Task { await model.captureNow() }
             } label: {
-                actionLabel("Capture now", trailing: "⌥⇧2")
+                actionLabel("Capture now", trailing: model.hotkeyDisplayString)
             }
             .disabled(model.isCapturing)
 

Sources/Shotdeck/PickerSelfTest.swift

@@ -113,8 +113,11 @@ enum PickerSelfTest {
         fflush(stdout)
 
         runRegionPersistPhase()
+        if !startUpdateSelfTestIfRequested() {
             exit(0)
         }
+        // UPDATE-SELFTEST hops to a later main-actor turn and exits itself.
+    }
 
     /// Phase 2: writes a known region under `CaptureRegion.defaultsKey`, reloads it through
     /// `AppModel.loadPersistedRegion()` (the same path init uses), then restores whatever
@@ -157,6 +160,179 @@ enum PickerSelfTest {
         fflush(stdout)
     }
 
+    /// Phase 3: builds a fake 99.0.0 bundle, serves a local appcast, stages via
+    /// `checkNow`, then `installStaged` into the env dir — never `/Applications`.
+    /// Returns true when the async phase was scheduled (it calls `exit` itself).
+    @discardableResult
+    private static func startUpdateSelfTestIfRequested() -> Bool {
+        guard let raw = ProcessInfo.processInfo.environment["SHOTDECK_UPDATE_SELFTEST"],
+              !raw.isEmpty
+        else { return false }
+
+        let output = URL(fileURLWithPath: raw, isDirectory: true)
+        Task { @MainActor in
+            do {
+                try await runUpdateSelfTest(outputDirectory: output)
+                print("UPDATE-SELFTEST PASS version=99.0.0")
+                fflush(stdout)
+                exit(0)
+            } catch let error as UpdateSelfTestError {
+                updateFail(error.description)
+            } catch {
+                updateFail(String(describing: error))
+            }
+        }
+        return true
+    }
+
+    private static func runUpdateSelfTest(outputDirectory: URL) async throws {
+        let fm = FileManager.default
+        try fm.createDirectory(at: outputDirectory, withIntermediateDirectories: true)
+
+        guard let sourceApp = ownAppBundleURL() else {
+            throw UpdateSelfTestError.detail("own bundle is not a .app (\(Bundle.main.bundleURL.path))")
+        }
+
+        let payload = outputDirectory.appendingPathComponent("payload", isDirectory: true)
+        if fm.fileExists(atPath: payload.path) {
+            try fm.removeItem(at: payload)
+        }
+        try fm.createDirectory(at: payload, withIntermediateDirectories: true)
+        let fakeApp = payload.appendingPathComponent("Redline.app")
+        try fm.copyItem(at: sourceApp, to: fakeApp)
+
+        let plistURL = fakeApp.appendingPathComponent("Contents/Info.plist")
+        let plistData = try Data(contentsOf: plistURL)
+        guard var plist = try PropertyListSerialization.propertyList(from: plistData, format: nil) as? [String: Any] else {
+            throw UpdateSelfTestError.detail("could not parse copied Info.plist")
+        }
+        plist["CFBundleShortVersionString"] = "99.0.0"
+        let rewritten = try PropertyListSerialization.data(fromPropertyList: plist, format: .xml, options: 0)
+        try rewritten.write(to: plistURL)
+
+        let zipURL = outputDirectory.appendingPathComponent("Redline-99.0.0.zip")
+        if fm.fileExists(atPath: zipURL.path) {
+            try fm.removeItem(at: zipURL)
+        }
+        try runDitto(arguments: ["-c", "-k", payload.path, zipURL.path])
+
+        let zipData = try Data(contentsOf: zipURL)
+        let hex = UpdateChecker.sha256Hex(zipData)
+
+        let appcastURL = outputDirectory.appendingPathComponent("appcast.json")
+        let appcast: [String: String] = [
+            "version": "99.0.0",
+            "zipURL": zipURL.absoluteString,
+            "sha256": hex,
+            "notes": "UPDATE-SELFTEST",
+        ]
+        let appcastData = try JSONSerialization.data(withJSONObject: appcast, options: [.sortedKeys])
+        try appcastData.write(to: appcastURL)
+
+        let defaults = UserDefaults.standard
+        let previous = defaults.string(forKey: UpdateChecker.appcastURLDefaultsKey)
+        defaults.set(appcastURL.absoluteString, forKey: UpdateChecker.appcastURLDefaultsKey)
+        defer {
+            if let previous {
+                defaults.set(previous, forKey: UpdateChecker.appcastURLDefaultsKey)
+            } else {
+                defaults.removeObject(forKey: UpdateChecker.appcastURLDefaultsKey)
+            }
+        }
+
+        let (model, isolatedRoot) = try makeIsolatedUpdateModel()
+        defer { try? fm.removeItem(at: isolatedRoot) }
+
+        await model.updateChecker.checkNow()
+
+        guard model.updateAvailable?.version == "99.0.0" else {
+            throw UpdateSelfTestError.detail(
+                "updateAvailable=\(model.updateAvailable?.version ?? "nil")"
+            )
+        }
+        guard let staged = model.updateChecker.stagedAppURL else {
+            throw UpdateSelfTestError.detail("staged payload missing")
+        }
+        guard staged.lastPathComponent == "Redline.app" else {
+            throw UpdateSelfTestError.detail("staged name \(staged.lastPathComponent)")
+        }
+        let stagedExe = staged.appendingPathComponent("Contents/MacOS/Shotdeck")
+        guard fm.fileExists(atPath: stagedExe.path) else {
+            throw UpdateSelfTestError.detail("staged Contents/MacOS/Shotdeck missing")
+        }
+
+        let targetRoot = outputDirectory.appendingPathComponent("target", isDirectory: true)
+        if fm.fileExists(atPath: targetRoot.path) {
+            try fm.removeItem(at: targetRoot)
+        }
+        let target = targetRoot.appendingPathComponent("Redline.app")
+        model.updateChecker.installStaged(to: target)
+
+        let installedPlist = target.appendingPathComponent("Contents/Info.plist")
+        guard let installed = NSDictionary(contentsOf: installedPlist) as? [String: Any],
+              let installedVersion = installed["CFBundleShortVersionString"] as? String
+        else {
+            throw UpdateSelfTestError.detail("installed Info.plist unreadable")
+        }
+        guard installedVersion == "99.0.0" else {
+            throw UpdateSelfTestError.detail("installed version \(installedVersion)")
+        }
+    }
+
+    private static func ownAppBundleURL() -> URL? {
+        let bundle = Bundle.main.bundleURL
+        if bundle.pathExtension == "app" { return bundle }
+        let up3 = bundle
+            .deletingLastPathComponent()
+            .deletingLastPathComponent()
+            .deletingLastPathComponent()
+        if up3.pathExtension == "app" { return up3 }
+        return nil
+    }
+
+    private static func makeIsolatedUpdateModel() throws -> (AppModel, URL) {
+        let root = FileManager.default.temporaryDirectory
+            .appendingPathComponent("shotdeck-update-selftest-\(UUID().uuidString)", isDirectory: true)
+        let paths = try AppSupportPaths(
+            root: root,
+            outbox: root.appendingPathComponent("outbox", isDirectory: true),
+            watchFolder: root.appendingPathComponent("watch", isDirectory: true)
+        )
+        let ledger = try ReturnLedger(paths: paths)
+        let model = AppModel(
+            paths: paths,
+            spool: try SpoolStore(paths: paths),
+            composer: PDFComposer(),
+            capturer: ScreenCapturer(),
+            hotkeys: HotkeyCenter(),
+            picker: RegionPickerController(),
+            ledger: ledger,
+            watcher: ReturnWatcher(paths: paths, ledger: ledger)
+        )
+        return (model, root)
+    }
+
+    private static func runDitto(arguments: [String]) throws {
+        let process = Process()
+        process.executableURL = URL(fileURLWithPath: "/usr/bin/ditto")
+        process.arguments = arguments
+        let err = Pipe()
+        process.standardError = err
+        process.standardOutput = Pipe()
+        try process.run()
+        process.waitUntilExit()
+        guard process.terminationStatus == 0 else {
+            let message = String(data: err.fileHandleForReading.readDataToEndOfFile(), encoding: .utf8) ?? ""
+            throw UpdateSelfTestError.detail("ditto failed: \(message)")
+        }
+    }
+
+    private static func updateFail(_ detail: String) -> Never {
+        print("UPDATE-SELFTEST FAIL \(detail)")
+        fflush(stdout)
+        exit(1)
+    }
+
     private static func interpolate(_ step: Int) -> NSPoint {
         let t = CGFloat(step) / CGFloat(dragSteps)
         return NSPoint(
@@ -213,3 +389,12 @@ enum PickerSelfTest {
         exit(1)
     }
 }
+
+private enum UpdateSelfTestError: Error, CustomStringConvertible {
+    case detail(String)
+    var description: String {
+        switch self {
+        case .detail(let s): return s
+        }
+    }
+}

Sources/Shotdeck/SettingsView.swift

@@ -4,6 +4,8 @@ import ShotdeckCore
 
 struct SettingsView: View {
     @Environment(AppModel.self) private var model
+    @State private var isRecordingHotkey = false
+    @State private var recorder = HotkeyRecorderBox()
 
     private let labelWidth: CGFloat = 104
 
@@ -16,13 +18,19 @@ struct SettingsView: View {
                     .gridCellColumns(2)
             }
 
-            GridRow(alignment: .firstTextBaseline) {
+            GridRow(alignment: .center) {
                 fieldLabel("Capture")
-                Text("⌥⇧2 — fixed in this version")
+                HStack(spacing: 8) {
-                    .foregroundStyle(.secondary)
+                    Button {
+                        armHotkeyRecorder()
+                    } label: {
+                        Text(isRecordingHotkey ? "Press keys…" : model.hotkeyDisplayString)
+                            .foregroundStyle(isRecordingHotkey ? .secondary : .primary)
                             .lineLimit(1)
-                    .frame(maxWidth: .infinity, alignment: .leading)
+                    }
-                    .frame(minHeight: 22, alignment: .leading)
+                    Spacer(minLength: 0)
+                }
+                .frame(minHeight: 22)
             }
 
             GridRow {
@@ -57,6 +65,35 @@ struct SettingsView: View {
         .padding(16)
         .frame(minWidth: 320, idealWidth: 360, maxWidth: 360, alignment: .leading)
         .controlSize(.small)
+        .onDisappear { disarmHotkeyRecorder() }
+    }
+
+    private func armHotkeyRecorder() {
+        guard !isRecordingHotkey else { return }
+        isRecordingHotkey = true
+        recorder.onKey = { keyCode, flags in
+            handleRecorderKey(keyCode: keyCode, flags: flags)
+        }
+        recorder.arm()
+    }
+
+    private func handleRecorderKey(keyCode: UInt16, flags: NSEvent.ModifierFlags) {
+        if keyCode == 53 { // kVK_Escape
+            disarmHotkeyRecorder()
+            return
+        }
+        guard let pref = HotkeyPreference.fromKeyEvent(keyCode: keyCode, modifierFlags: flags) else {
+            return
+        }
+        pref.save()
+        model.reRegisterHotkey()
+        disarmHotkeyRecorder()
+    }
+
+    private func disarmHotkeyRecorder() {
+        recorder.disarm()
+        recorder.onKey = nil
+        isRecordingHotkey = false
     }
 
     private func fieldLabel(_ title: String) -> some View {
@@ -80,6 +117,35 @@ struct SettingsView: View {
     }
 }
 
+/// Local keyDown monitor for the Settings capture-hotkey recorder. Callbacks hop onto the
+/// main actor the same way `RegionPickerController` does — local monitors fire on the
+/// main run loop during `NSApp.sendEvent`.
+@MainActor
+private final class HotkeyRecorderBox {
+    var onKey: ((UInt16, NSEvent.ModifierFlags) -> Void)?
+    private var monitor: Any?
+
+    func arm() {
+        disarm()
+        monitor = NSEvent.addLocalMonitorForEvents(matching: .keyDown) { [weak self] event in
+            guard let self else { return event }
+            let keyCode = event.keyCode
+            let rawFlags = event.modifierFlags.rawValue
+            MainActor.assumeIsolated {
+                self.onKey?(keyCode, NSEvent.ModifierFlags(rawValue: rawFlags))
+            }
+            return nil
+        }
+    }
+
+    func disarm() {
+        if let monitor {
+            NSEvent.removeMonitor(monitor)
+        }
+        monitor = nil
+    }
+}
+
 extension AppModel: SettingsWindowPresenting {
     private static var settingsWindowController: NSWindowController?
 

Sources/Shotdeck/UpdateChecker.swift

@@ -0,0 +1,281 @@
+import AppKit
+import CryptoKit
+import Foundation
+
+/// Built-in updater. Checks an appcast, stages a verified payload, and installs
+/// only when the user clicks the menu row — never automatically.
+@MainActor
+final class UpdateChecker {
+    static let appcastURLDefaultsKey = "ai.flowmaster.shotdeck.appcastURL"
+    static let defaultAppcastURL = URL(string: "https://get.baobab-ts.com/cowork/redline/appcast.json")!
+    static let defaultInstallTarget = URL(fileURLWithPath: "/Applications/Redline.app")
+
+    private(set) var availableUpdate: (version: String, notes: String)?
+    private(set) var stagedAppURL: URL?
+    private(set) var statusMessage: String?
+
+    var onChecked: (() -> Void)?
+
+    private let urlSession: URLSession
+    private var repeatingTimer: Timer?
+    private var firstCheckTask: Task<Void, Never>?
+    private var isChecking = false
+    private var stagingDirectory: URL?
+
+    init() {
+        let config = URLSessionConfiguration.ephemeral
+        config.timeoutIntervalForRequest = 15
+        config.timeoutIntervalForResource = 15
+        config.httpCookieAcceptPolicy = .never
+        config.httpShouldSetCookies = false
+        config.httpCookieStorage = nil
+        config.urlCache = nil
+        urlSession = URLSession(configuration: config)
+    }
+
+    /// First check 10 seconds after start, then every 6 hours. Stages only — never installs.
+    func startSchedule() {
+        firstCheckTask?.cancel()
+        firstCheckTask = Task { [weak self] in
+            try? await Task.sleep(for: .seconds(10))
+            guard !Task.isCancelled else { return }
+            await self?.checkNow()
+        }
+        repeatingTimer?.invalidate()
+        let timer = Timer(timeInterval: 6 * 60 * 60, repeats: true) { [weak self] _ in
+            Task { @MainActor in
+                await self?.checkNow()
+            }
+        }
+        RunLoop.main.add(timer, forMode: .common)
+        repeatingTimer = timer
+    }
+
+    func checkNow() async {
+        guard !isChecking else { return }
+        isChecking = true
+        defer { isChecking = false }
+
+        let appcast: Appcast
+        do {
+            appcast = try await fetchAppcast()
+        } catch {
+            statusMessage = "Could not check for updates."
+            onChecked?()
+            return
+        }
+
+        guard Self.isNewer(appcast.version, than: Self.currentVersion()) else {
+            clearOffer()
+            statusMessage = nil
+            onChecked?()
+            return
+        }
+
+        do {
+            try await downloadAndStage(appcast)
+            availableUpdate = (version: appcast.version, notes: appcast.notes ?? "")
+            statusMessage = nil
+        } catch UpdateCheckError.checksumMismatch {
+            discardStaging()
+            availableUpdate = nil
+            statusMessage = "Update file failed the checksum — not installed."
+        } catch {
+            discardStaging()
+            availableUpdate = nil
+            statusMessage = "The update could not be prepared."
+        }
+        onChecked?()
+    }
+
+    /// Copies the staged app onto `target` with ditto (in place; never deletes the old app).
+    /// Relaunches unless `SHOTDECK_UPDATE_SELFTEST` is set, so the in-process self-test
+    /// can assert the installed Info.plist without killing the process.
+    func installStaged(to target: URL = UpdateChecker.defaultInstallTarget) {
+        guard let staged = stagedAppURL else {
+            statusMessage = "No update is staged."
+            onChecked?()
+            return
+        }
+
+        do {
+            try FileManager.default.createDirectory(
+                at: target.deletingLastPathComponent(),
+                withIntermediateDirectories: true
+            )
+            try Self.runProcess(executable: "/usr/bin/ditto", arguments: [staged.path, target.path])
+        } catch {
+            statusMessage = "The update could not be installed."
+            onChecked?()
+            return
+        }
+
+        let isSelfTest = ProcessInfo.processInfo.environment["SHOTDECK_UPDATE_SELFTEST"] != nil
+        if isSelfTest { return }
+
+        do {
+            try Self.runProcess(executable: "/usr/bin/open", arguments: ["-n", target.path])
+        } catch {
+            statusMessage = "The update was installed but Redline could not relaunch. Open it from Applications."
+            onChecked?()
+            return
+        }
+        NSApp.terminate(nil)
+    }
+
+    static func resolvedAppcastURL() -> URL {
+        if let env = ProcessInfo.processInfo.environment["REDLINE_APPCAST_URL"],
+           !env.isEmpty,
+           let url = URL(string: env)
+        {
+            return url
+        }
+        if let stored = UserDefaults.standard.string(forKey: appcastURLDefaultsKey),
+           !stored.isEmpty,
+           let url = URL(string: stored)
+        {
+            return url
+        }
+        return defaultAppcastURL
+    }
+
+    static func currentVersion() -> String {
+        Bundle.main.object(forInfoDictionaryKey: "CFBundleShortVersionString") as? String ?? "0.0.0"
+    }
+
+    static func isNewer(_ candidate: String, than current: String) -> Bool {
+        let a = semverParts(candidate)
+        let b = semverParts(current)
+        for i in 0..<3 {
+            if a[i] != b[i] { return a[i] > b[i] }
+        }
+        return false
+    }
+
+    static func sha256Hex(_ data: Data) -> String {
+        SHA256.hash(data: data).map { String(format: "%02x", $0) }.joined()
+    }
+
+    // MARK: - Private
+
+    private struct Appcast: Decodable {
+        var version: String
+        var zipURL: URL
+        var sha256: String
+        var notes: String?
+    }
+
+    private enum UpdateCheckError: Error {
+        case checksumMismatch
+        case invalidPayload
+        case httpStatus(Int)
+        case processFailed(String)
+    }
+
+    private func fetchAppcast() async throws -> Appcast {
+        let data = try await fetchData(from: Self.resolvedAppcastURL())
+        return try JSONDecoder().decode(Appcast.self, from: data)
+    }
+
+    private func fetchData(from url: URL) async throws -> Data {
+        if url.isFileURL {
+            return try Data(contentsOf: url)
+        }
+        let (data, response) = try await urlSession.data(from: url)
+        if let http = response as? HTTPURLResponse, !(200...299).contains(http.statusCode) {
+            throw UpdateCheckError.httpStatus(http.statusCode)
+        }
+        return data
+    }
+
+    private func downloadAndStage(_ appcast: Appcast) async throws {
+        let zipData = try await fetchData(from: appcast.zipURL)
+        let expected = appcast.sha256.trimmingCharacters(in: .whitespacesAndNewlines)
+        let actual = Self.sha256Hex(zipData)
+        guard actual.caseInsensitiveCompare(expected) == .orderedSame else {
+            throw UpdateCheckError.checksumMismatch
+        }
+
+        discardStaging()
+        let root = FileManager.default.temporaryDirectory
+            .appendingPathComponent("shotdeck-update-\(UUID().uuidString)", isDirectory: true)
+        try FileManager.default.createDirectory(at: root, withIntermediateDirectories: true)
+        stagingDirectory = root
+
+        let zipURL = root.appendingPathComponent("update.zip")
+        try zipData.write(to: zipURL)
+
+        let extracted = root.appendingPathComponent("extracted", isDirectory: true)
+        try FileManager.default.createDirectory(at: extracted, withIntermediateDirectories: true)
+        try Self.runProcess(
+            executable: "/usr/bin/ditto",
+            arguments: ["-x", "-k", zipURL.path, extracted.path]
+        )
+
+        guard let appURL = Self.findRedlineApp(in: extracted) else {
+            throw UpdateCheckError.invalidPayload
+        }
+        let executable = appURL.appendingPathComponent("Contents/MacOS/Shotdeck")
+        guard FileManager.default.fileExists(atPath: executable.path) else {
+            throw UpdateCheckError.invalidPayload
+        }
+        stagedAppURL = appURL
+    }
+
+    private func clearOffer() {
+        availableUpdate = nil
+        discardStaging()
+    }
+
+    private func discardStaging() {
+        if let stagingDirectory {
+            try? FileManager.default.removeItem(at: stagingDirectory)
+        }
+        stagingDirectory = nil
+        stagedAppURL = nil
+    }
+
+    private static func findRedlineApp(in directory: URL) -> URL? {
+        let fm = FileManager.default
+        let direct = directory.appendingPathComponent("Redline.app")
+        if fm.fileExists(atPath: direct.path) { return direct }
+
+        guard let enumerator = fm.enumerator(
+            at: directory,
+            includingPropertiesForKeys: [.isDirectoryKey],
+            options: [.skipsHiddenFiles]
+        ) else { return nil }
+
+        while let item = enumerator.nextObject() as? URL {
+            if item.lastPathComponent == "Redline.app" {
+                return item
+            }
+            if item.pathExtension == "app" {
+                enumerator.skipDescendants()
+            }
+        }
+        return nil
+    }
+
+    private static func semverParts(_ string: String) -> [Int] {
+        let core = string.split(separator: "-").first.map(String.init) ?? string
+        var parts = core.split(separator: ".").prefix(3).map { Int($0) ?? 0 }
+        while parts.count < 3 { parts.append(0) }
+        return parts
+    }
+
+    private static func runProcess(executable: String, arguments: [String]) throws {
+        let process = Process()
+        process.executableURL = URL(fileURLWithPath: executable)
+        process.arguments = arguments
+        let err = Pipe()
+        process.standardError = err
+        process.standardOutput = Pipe()
+        try process.run()
+        process.waitUntilExit()
+        guard process.terminationStatus == 0 else {
+            let message = String(data: err.fileHandleForReading.readDataToEndOfFile(), encoding: .utf8) ?? ""
+            throw UpdateCheckError.processFailed("\(executable) failed: \(message)")
+        }
+    }
+}