release: v0.3.2

REPLACED: three worthless tests that only tested test code, not production:
- statusMessageUpToDateFormat built the expected string locally and matched it
- statusMessageUpdateReadyFormat same self-referential test
- statusChannelsAreIndependent was literally #expect(true, ...)

ADDED: four real tests that drive production code:
- dubaiTimeCheckTimeFormat: assert DubaiTime.checkTime() formats as HH:MM Dubai
- manualCheckUpToDateIncludesTimestamp: inject stub appcast via testAppcastJSON seam,
  drive UpdateChecker.checkNow(manual: true), verify statusMessage matches exact format
- automaticCheckUpToDateLeavesMessageNil: verify automatic check (manual: false) leaves
  statusMessage nil when up-to-date
- statusChannelsAreIndependent: construct real AppModel via AppDelegate.makeLaunchModel(),
  assert setStatus() does NOT affect updateStatusMessage, setUpdateStatus() does NOT
  affect statusLine, and vice versa. PROVES the defect is caught: test fails with 3 issues
  if updateStatusMessage is reverted to an alias of statusLine.

ADDED: testAppcastJSON seam to UpdateChecker for test injection of appcast data.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012ZiTXPbPCSjzPVsfoweAbp

Info.plist

@@ -13,9 +13,9 @@
 	<key>CFBundlePackageType</key>
 	<string>APPL</string>
 	<key>CFBundleShortVersionString</key>
-	<string>0.3.0</string>
+	<string>0.3.2</string>
 	<key>CFBundleVersion</key>
-	<string>3</string>
+	<string>5</string>
 	<key>LSMinimumSystemVersion</key>
 	<string>14.0</string>
 	<key>LSUIElement</key>

Sources/Shotdeck/AppModel.swift

@@ -28,6 +28,7 @@ public final class AppModel {
     public private(set) var allReturns: [ReturnedDocument] = []
     public private(set) var commentedReturns: [ReturnedDocument] = []
     public private(set) var statusLine: String?
+    public private(set) var updateStatus: String?
     public private(set) var isCapturing: Bool = false
     public private(set) var isSending: Bool = false
     public private(set) var outboxDisplayName: String
@@ -51,6 +52,8 @@ public final class AppModel {
     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)?
+    /// True for the duration of any appcast check (manual or scheduled).
+    public private(set) var isCheckingForUpdates: Bool = false
 
     let paths: AppSupportPaths
     let spool: SpoolStore
@@ -104,15 +107,24 @@ public final class AppModel {
         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)
+            self.setUpdateStatus(self.updateChecker.statusMessage)
         }
+        self.updateChecker.onCheckingChanged = { [weak self] checking in
+            self?.isCheckingForUpdates = checking
         }
     }
 
+    /// CFBundleShortVersionString of the running app.
+    public var appVersion: String { UpdateChecker.currentVersion() }
+    /// Version recorded in the app-managed rollback copy, when one exists.
+    public var previousVersion: String? { updateChecker.previousVersion() }
+    /// Update-related status text (checked time, staged update, errors). Displayed only in the footer.
+    public var updateStatusMessage: String? { updateStatus }
+
     // MARK: Seam mutators — the only way a WP-4b/4c extension changes state.
 
     func setStatus(_ text: String?) { statusLine = text }
+    func setUpdateStatus(_ text: String?) { updateStatus = text }
     func setSending(_ value: Bool) { isSending = value }
     func setCapturing(_ value: Bool) { isCapturing = value }
     func replaceSession(_ new: CaptureSession) { session = new }
@@ -282,6 +294,19 @@ public final class AppModel {
         updateChecker.installStaged()
     }
 
+    /// User-initiated appcast check ("Check for updates" menu row).
+    public func checkForUpdates() {
+        Task { @MainActor in
+            await updateChecker.checkNow(manual: true)
+        }
+    }
+
+    /// Reverts `/Applications/Redline.app` to the app-managed rollback copy and relaunches.
+    /// Does nothing unless a `Redline.app.previous` exists and the user clicked the row.
+    public func revertToPreviousVersion() {
+        updateChecker.revertToPrevious()
+    }
+
     /// 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() {

Sources/Shotdeck/MenuBarView.swift

@@ -15,6 +15,8 @@ struct MenuBarView: View {
                 Divider()
                 returnsBlock
             }
+            Divider()
+            updateFooter
         }
         .padding(10)
         .frame(width: 320, alignment: .leading)
@@ -83,6 +85,21 @@ struct MenuBarView: View {
                 }
             }
 
+            Button {
+                model.checkForUpdates()
+            } label: {
+                actionLabel(model.isCheckingForUpdates ? "Checking…" : "Check for updates")
+            }
+            .disabled(model.isCheckingForUpdates)
+
+            if let previous = model.previousVersion {
+                Button {
+                    model.revertToPreviousVersion()
+                } label: {
+                    actionLabel("Revert to \(previous)")
+                }
+            }
+
             Button {
                 let anchor = NSApp.keyWindow?.contentView
                 if let sender = model as? SendCapable {
@@ -193,4 +210,18 @@ struct MenuBarView: View {
     private var newestReturns: [ReturnedDocument] {
         model.allReturns.sorted { $0.detectedAt > $1.detectedAt }
     }
+
+    private var updateFooter: some View {
+        VStack(alignment: .leading, spacing: 2) {
+            Text("Redline \(model.appVersion)")
+                .font(.caption)
+                .foregroundStyle(.secondary)
+            if let message = model.updateStatusMessage {
+                Text(message)
+                    .font(.caption)
+                    .foregroundStyle(.secondary)
+                    .fixedSize(horizontal: false, vertical: true)
+            }
+        }
+    }
 }

Sources/Shotdeck/PanelSnapshot.swift

@@ -155,6 +155,37 @@ enum PanelSnapshot {
         model.replaceRegion(sampleRegion())
         try await addSampleCaptures(to: model)
         try renderMenuBar(model: model, to: directory, name: "09-captures-present-onedrive")
+
+        // 10 — update idle: 3 captures, no update available, footer "Redline <ver>", row "Check for updates".
+        let (updateModel, updateRoot) = try makeIsolatedModel()
+        defer { try? FileManager.default.removeItem(at: updateRoot) }
+        updateModel.snapshotSetScreenRecordingGranted(true)
+        updateModel.replaceRegion(sampleRegion())
+        try await addSampleCaptures(to: updateModel)
+        // No update set, updateChecker in idle state, no previous version
+        updateModel.snapshotSetPreviousVersion(nil)
+        try renderMenuBar(model: updateModel, to: directory, name: "10-update-idle")
+
+        // 11 — update checking: same as 10 but isCheckingForUpdates = true.
+        updateModel.snapshotSetIsCheckingForUpdates(true)
+        try renderMenuBar(model: updateModel, to: directory, name: "11-update-checking")
+        updateModel.snapshotSetIsCheckingForUpdates(false)
+
+        // 12 — update up-to-date: footer status line reads "Redline <ver> is up to date, checked 10:42 Dubai".
+        let upToDateMessage = "Redline \(updateModel.appVersion) is up to date, checked 10:42 Dubai"
+        updateModel.snapshotSetUpdateStatusMessage(upToDateMessage)
+        try renderMenuBar(model: updateModel, to: directory, name: "12-update-uptodate")
+
+        // 13 — update staged: row "Update to 9.9.9" present, footer status "Update to 9.9.9 is ready".
+        updateModel.snapshotSetUpdateAvailable(version: "9.9.9", notes: "Test release")
+        updateModel.snapshotSetUpdateStatusMessage("Update to 9.9.9 is ready")
+        try renderMenuBar(model: updateModel, to: directory, name: "13-update-staged")
+
+        // 14 — update revert: row "Revert to 0.2.0" present.
+        updateModel.snapshotSetUpdateAvailable(version: nil, notes: nil)  // Clear the staged update
+        updateModel.snapshotSetUpdateStatusMessage(nil)
+        updateModel.snapshotSetPreviousVersion("0.2.0")
+        try renderMenuBar(model: updateModel, to: directory, name: "14-update-revert")
     }
 
     @MainActor
@@ -360,6 +391,40 @@ extension AppModel {
         )
         self[keyPath: writable] = granted
     }
+
+    /// Snapshot-only: set isCheckingForUpdates without triggering a real check.
+    func snapshotSetIsCheckingForUpdates(_ checking: Bool) {
+        let writable: ReferenceWritableKeyPath<AppModel, Bool> = unsafeBitCast(
+            \AppModel.isCheckingForUpdates, to: ReferenceWritableKeyPath<AppModel, Bool>.self
+        )
+        self[keyPath: writable] = checking
+    }
+
+    /// Snapshot-only: set updateStatusMessage for panel display.
+    func snapshotSetUpdateStatusMessage(_ message: String?) {
+        setUpdateStatus(message)
+    }
+
+    /// Snapshot-only: set updateAvailable without triggering a real download.
+    func snapshotSetUpdateAvailable(version: String?, notes: String?) {
+        if let version = version, let notes = notes {
+            let writable: ReferenceWritableKeyPath<AppModel, (version: String, notes: String)?> = unsafeBitCast(
+                \AppModel.updateAvailable, to: ReferenceWritableKeyPath<AppModel, (version: String, notes: String)?>.self
+            )
+            self[keyPath: writable] = (version: version, notes: notes)
+        } else {
+            let writable: ReferenceWritableKeyPath<AppModel, (version: String, notes: String)?> = unsafeBitCast(
+                \AppModel.updateAvailable, to: ReferenceWritableKeyPath<AppModel, (version: String, notes: String)?>.self
+            )
+            self[keyPath: writable] = nil
+        }
+    }
+
+    /// Snapshot-only: set a fake previousVersion for the revert panel.
+    func snapshotSetPreviousVersion(_ version: String?) {
+        updateChecker.snapshotPreviousVersionOverride = version
+        updateChecker.snapshotUsesPreviousVersionOverride = true
+    }
 }
 
 private enum SnapshotError: Error, CustomStringConvertible {

Sources/Shotdeck/PickerSelfTest.swift

@@ -328,6 +328,9 @@ enum PickerSelfTest {
         return true
     }
 
+    /// (a) rejects an invalidly-signed payload, (b) stages the same payload once
+    /// properly signed, (c) installs it atomically into a throwaway target with
+    /// exactly one rollback copy, (d) reverts back. Never touches `/Applications`.
     private static func runUpdateSelfTest(outputDirectory: URL) async throws {
         let fm = FileManager.default
         try fm.createDirectory(at: outputDirectory, withIntermediateDirectories: true)
@@ -335,6 +338,9 @@ enum PickerSelfTest {
         guard let sourceApp = ownAppBundleURL() else {
             throw UpdateSelfTestError.detail("own bundle is not a .app (\(Bundle.main.bundleURL.path))")
         }
+        guard let originalVersion = readShortVersion(atAppURL: sourceApp) else {
+            throw UpdateSelfTestError.detail("own Info.plist has no CFBundleShortVersionString")
+        }
 
         let payload = outputDirectory.appendingPathComponent("payload", isDirectory: true)
         if fm.fileExists(atPath: payload.path) {
@@ -352,17 +358,20 @@ enum PickerSelfTest {
         plist["CFBundleShortVersionString"] = "99.0.0"
         let rewritten = try PropertyListSerialization.data(fromPropertyList: plist, format: .xml, options: 0)
         try rewritten.write(to: plistURL)
+        // Editing Info.plist after copying it invalidates the inherited signature —
+        // Info.plist is a sealed special slot in the CodeDirectory — so this fake
+        // bundle is genuinely unsigned-in-effect without us stripping anything.
 
         let zipURL = outputDirectory.appendingPathComponent("Redline-99.0.0.zip")
+        let appcastURL = outputDirectory.appendingPathComponent("appcast.json")
+
+        func writeZipAndAppcast() throws {
             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,
@@ -371,13 +380,15 @@ enum PickerSelfTest {
             ]
             let appcastData = try JSONSerialization.data(withJSONObject: appcast, options: [.sortedKeys])
             try appcastData.write(to: appcastURL)
+        }
+        try writeZipAndAppcast()
 
         let defaults = UserDefaults.standard
-        let previous = defaults.string(forKey: UpdateChecker.appcastURLDefaultsKey)
+        let previousAppcastPref = defaults.string(forKey: UpdateChecker.appcastURLDefaultsKey)
         defaults.set(appcastURL.absoluteString, forKey: UpdateChecker.appcastURLDefaultsKey)
         defer {
-            if let previous {
-                defaults.set(previous, forKey: UpdateChecker.appcastURLDefaultsKey)
+            if let previousAppcastPref {
+                defaults.set(previousAppcastPref, forKey: UpdateChecker.appcastURLDefaultsKey)
             } else {
                 defaults.removeObject(forKey: UpdateChecker.appcastURLDefaultsKey)
             }
@@ -386,39 +397,128 @@ enum PickerSelfTest {
         let (model, isolatedRoot) = try makeIsolatedUpdateModel()
         defer { try? fm.removeItem(at: isolatedRoot) }
 
+        // (a) NEGATIVE — invalidly-signed payload must never be offered or staged.
         await model.updateChecker.checkNow()
+        guard model.updateAvailable == nil else {
+            throw UpdateSelfTestError.detail(
+                "reject-unsigned: updateAvailable=\(model.updateAvailable?.version ?? "nil") (expected nil)"
+            )
+        }
+        guard model.updateChecker.statusMessage == "Update is not signed by MMD — not installed." else {
+            throw UpdateSelfTestError.detail(
+                "reject-unsigned: statusMessage=\(model.updateChecker.statusMessage ?? "nil")"
+            )
+        }
+        print("UPDATE-SELFTEST reject-unsigned PASS")
+        fflush(stdout)
 
+        // (b) POSITIVE — re-sign the same bundle, re-zip, re-serve; must now stage.
+        let signIdentity = ProcessInfo.processInfo.environment["SHOTDECK_SELFTEST_SIGN_IDENTITY"]
+            ?? "Apple Development: ben@flow-master.ai (QH2H9G2LK5)"
+        try runCodesign(identity: signIdentity, path: fakeApp.path)
+        try writeZipAndAppcast()
+
+        await model.updateChecker.checkNow()
         guard model.updateAvailable?.version == "99.0.0" else {
             throw UpdateSelfTestError.detail(
-                "updateAvailable=\(model.updateAvailable?.version ?? "nil")"
+                "staged-signed: updateAvailable=\(model.updateAvailable?.version ?? "nil")"
             )
         }
         guard let staged = model.updateChecker.stagedAppURL else {
-            throw UpdateSelfTestError.detail("staged payload missing")
+            throw UpdateSelfTestError.detail("staged-signed: staged payload missing")
         }
         guard staged.lastPathComponent == "Redline.app" else {
-            throw UpdateSelfTestError.detail("staged name \(staged.lastPathComponent)")
+            throw UpdateSelfTestError.detail("staged-signed: 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")
+            throw UpdateSelfTestError.detail("staged-signed: staged Contents/MacOS/Shotdeck missing")
         }
+        print("UPDATE-SELFTEST staged-signed PASS")
+        fflush(stdout)
 
-        let targetRoot = outputDirectory.appendingPathComponent("target", isDirectory: true)
-        if fm.fileExists(atPath: targetRoot.path) {
-            try fm.removeItem(at: targetRoot)
+        // (c) ATOMIC INSTALL — a throwaway target pre-populated with the real
+        // running version; never `/Applications`.
+        let tempAppsRoot = outputDirectory.appendingPathComponent("Applications", isDirectory: true)
+        if fm.fileExists(atPath: tempAppsRoot.path) {
+            try fm.removeItem(at: tempAppsRoot)
         }
-        let target = targetRoot.appendingPathComponent("Redline.app")
-        model.updateChecker.installStaged(to: target)
+        try fm.createDirectory(at: tempAppsRoot, withIntermediateDirectories: true)
+        let tempTarget = tempAppsRoot.appendingPathComponent("Redline.app")
+        try fm.copyItem(at: sourceApp, to: tempTarget)
 
-        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")
+        model.updateChecker.installStaged(to: tempTarget)
+
+        guard let installedVersion = readShortVersion(atAppURL: tempTarget) else {
+            throw UpdateSelfTestError.detail("atomic-install: installed Info.plist unreadable")
         }
         guard installedVersion == "99.0.0" else {
-            throw UpdateSelfTestError.detail("installed version \(installedVersion)")
+            throw UpdateSelfTestError.detail("atomic-install: installed version \(installedVersion)")
+        }
+        let previousCopy = tempAppsRoot.appendingPathComponent("Redline.app.previous")
+        guard let previousVersionAfterInstall = readShortVersion(atAppURL: previousCopy) else {
+            throw UpdateSelfTestError.detail("atomic-install: Redline.app.previous missing or unreadable")
+        }
+        guard previousVersionAfterInstall == originalVersion else {
+            throw UpdateSelfTestError.detail(
+                "atomic-install: previous version=\(previousVersionAfterInstall) expected=\(originalVersion)"
+            )
+        }
+        try assertNoLeftoverEntries(in: tempAppsRoot, expecting: ["Redline.app", "Redline.app.previous"])
+        print("UPDATE-SELFTEST atomic-install PASS")
+        fflush(stdout)
+
+        // (d) REVERT — the rollback copy swaps back in; the just-replaced version
+        // becomes the new rollback copy, so a revert is itself reversible.
+        model.updateChecker.revertToPrevious(target: tempTarget)
+
+        guard let revertedVersion = readShortVersion(atAppURL: tempTarget) else {
+            throw UpdateSelfTestError.detail("revert: reverted Info.plist unreadable")
+        }
+        guard revertedVersion == originalVersion else {
+            throw UpdateSelfTestError.detail("revert: target version=\(revertedVersion) expected=\(originalVersion)")
+        }
+        guard let previousVersionAfterRevert = readShortVersion(atAppURL: previousCopy) else {
+            throw UpdateSelfTestError.detail("revert: Redline.app.previous missing or unreadable")
+        }
+        guard previousVersionAfterRevert == "99.0.0" else {
+            throw UpdateSelfTestError.detail(
+                "revert: previous version=\(previousVersionAfterRevert) expected=99.0.0"
+            )
+        }
+        try assertNoLeftoverEntries(in: tempAppsRoot, expecting: ["Redline.app", "Redline.app.previous"])
+        print("UPDATE-SELFTEST revert PASS")
+        fflush(stdout)
+    }
+
+    private static func readShortVersion(atAppURL url: URL) -> String? {
+        let plistURL = url.appendingPathComponent("Contents/Info.plist")
+        guard let dict = NSDictionary(contentsOf: plistURL) as? [String: Any] else { return nil }
+        return dict["CFBundleShortVersionString"] as? String
+    }
+
+    private static func runCodesign(identity: String, path: String) throws {
+        let process = Process()
+        process.executableURL = URL(fileURLWithPath: "/usr/bin/codesign")
+        process.arguments = ["--force", "--deep", "--sign", identity, path]
+        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("codesign failed: \(message)")
+        }
+    }
+
+    private static func assertNoLeftoverEntries(in directory: URL, expecting expected: Set<String>) throws {
+        let entries = (try? FileManager.default.contentsOfDirectory(atPath: directory.path)) ?? []
+        let unexpected = entries.filter { !expected.contains($0) }
+        guard unexpected.isEmpty else {
+            throw UpdateSelfTestError.detail(
+                "unexpected entries in \(directory.path): \(unexpected.joined(separator: ", "))"
+            )
         }
     }
 

Sources/Shotdeck/UpdateChecker.swift

@@ -1,6 +1,8 @@
 import AppKit
 import CryptoKit
 import Foundation
+import Security
+import ShotdeckCore
 
 /// Built-in updater. Checks an appcast, stages a verified payload, and installs
 /// only when the user clicks the menu row — never automatically.
@@ -10,22 +12,37 @@ final class UpdateChecker {
     static let defaultAppcastURL = URL(string: "https://get.baobab-ts.com/cowork/redline/appcast.json")!
     static let defaultInstallTarget = URL(fileURLWithPath: "/Applications/Redline.app")
 
+    /// Required bundle identifier for any staged or installed payload.
+    static let expectedBundleIdentifier = "ai.flowmaster.shotdeck"
+    /// Developer team identifiers MMD ships Redline under. Overridable only for the self-test.
+    static let allowedTeamIdentifiers: Set<String> = ["PWMCBMX5M8", "L3N9S54CN3"]
+
     private(set) var availableUpdate: (version: String, notes: String)?
     private(set) var stagedAppURL: URL?
     private(set) var statusMessage: String?
+    private(set) var lastCheckedAt: Date?
+    private(set) var isCheckingNow: Bool = false
 
     var onChecked: (() -> Void)?
+    /// Fired whenever `isCheckingNow` flips, so a UI can show "Checking…" for the
+    /// whole duration of a check rather than only after it lands.
+    var onCheckingChanged: ((Bool) -> Void)?
 
     private let urlSession: URLSession
     private var repeatingTimer: Timer?
     private var firstCheckTask: Task<Void, Never>?
-    private var isChecking = false
     private var stagingDirectory: URL?
+    /// Snapshot-only override for previousVersion; when snapshotUsesPreviousVersionOverride is true,
+    /// this value (including nil) is returned instead of checking the file system.
+    var snapshotPreviousVersionOverride: String?
+    var snapshotUsesPreviousVersionOverride: Bool = false
+    /// Test seam: override appcast JSON. When set, returns this instead of fetching from URL.
+    var testAppcastJSON: String?
 
     init() {
         let config = URLSessionConfiguration.ephemeral
-        config.timeoutIntervalForRequest = 15
-        config.timeoutIntervalForResource = 15
+        config.timeoutIntervalForRequest = 30
+        config.timeoutIntervalForResource = 600
         config.httpCookieAcceptPolicy = .never
         config.httpShouldSetCookies = false
         config.httpCookieStorage = nil
@@ -51,10 +68,18 @@ final class UpdateChecker {
         repeatingTimer = timer
     }
 
-    func checkNow() async {
-        guard !isChecking else { return }
-        isChecking = true
-        defer { isChecking = false }
+    /// Checks the appcast and stages a newer, signature-verified payload.
+    /// `manual` only affects the status message shown when already up to date —
+    /// a user-initiated check says so; the silent background check stays quiet.
+    func checkNow(manual: Bool = false) async {
+        guard !isCheckingNow else { return }
+        isCheckingNow = true
+        onCheckingChanged?(true)
+        defer {
+            isCheckingNow = false
+            onCheckingChanged?(false)
+        }
+        lastCheckedAt = Date()
 
         let appcast: Appcast
         do {
@@ -67,7 +92,12 @@ final class UpdateChecker {
 
         guard Self.isNewer(appcast.version, than: Self.currentVersion()) else {
             clearOffer()
+            if manual {
+                let timestamp = DubaiTime.checkTime(lastCheckedAt ?? Date())
+                statusMessage = "Redline \(Self.currentVersion()) is up to date, checked \(timestamp)"
+            } else {
                 statusMessage = nil
+            }
             onChecked?()
             return
         }
@@ -75,11 +105,15 @@ final class UpdateChecker {
         do {
             try await downloadAndStage(appcast)
             availableUpdate = (version: appcast.version, notes: appcast.notes ?? "")
-            statusMessage = nil
+            statusMessage = manual ? "Update to \(appcast.version) is ready" : nil
         } catch UpdateCheckError.checksumMismatch {
             discardStaging()
             availableUpdate = nil
             statusMessage = "Update file failed the checksum — not installed."
+        } catch UpdateCheckError.signatureInvalid {
+            discardStaging()
+            availableUpdate = nil
+            statusMessage = "Update is not signed by MMD — not installed."
         } catch {
             discardStaging()
             availableUpdate = nil
@@ -88,9 +122,9 @@ final class UpdateChecker {
         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.
+    /// Installs the staged app onto `target` atomically, keeping exactly one rollback
+    /// copy (`Redline.app.previous`), then hands off to a relaunch and quits.
+    /// Never deletes the old app before the new one is verified in place.
     func installStaged(to target: URL = UpdateChecker.defaultInstallTarget) {
         guard let staged = stagedAppURL else {
             statusMessage = "No update is staged."
@@ -98,29 +132,121 @@ final class UpdateChecker {
             return
         }
 
+        let targetDir = target.deletingLastPathComponent()
+        let previousURL = targetDir.appendingPathComponent("Redline.app.previous")
+
         do {
-            try FileManager.default.createDirectory(
-                at: target.deletingLastPathComponent(),
-                withIntermediateDirectories: true
+            try FileManager.default.createDirectory(at: targetDir, withIntermediateDirectories: true)
+
+            let replacementDir = try FileManager.default.url(
+                for: .itemReplacementDirectory,
+                in: .userDomainMask,
+                appropriateFor: target,
+                create: true
             )
-            try Self.runProcess(executable: "/usr/bin/ditto", arguments: [staged.path, target.path])
+            defer { try? FileManager.default.removeItem(at: replacementDir) }
+
+            let newCopy = replacementDir.appendingPathComponent(target.lastPathComponent)
+            try Self.runProcess(executable: "/usr/bin/ditto", arguments: [staged.path, newCopy.path])
+
+            // Exactly one rollback copy is kept — drop any older one before this install.
+            if FileManager.default.fileExists(atPath: previousURL.path) {
+                try FileManager.default.removeItem(at: previousURL)
+            }
+
+            if FileManager.default.fileExists(atPath: target.path) {
+                _ = try FileManager.default.replaceItemAt(
+                    target,
+                    withItemAt: newCopy,
+                    backupItemName: previousURL.lastPathComponent,
+                    options: [.withoutDeletingBackupItem]
+                )
+            } else {
+                try FileManager.default.moveItem(at: newCopy, to: target)
+            }
         } catch {
             statusMessage = "The update could not be installed."
             onChecked?()
             return
         }
 
-        let isSelfTest = ProcessInfo.processInfo.environment["SHOTDECK_UPDATE_SELFTEST"] != nil
-        if isSelfTest { return }
-
+        // Defense in depth: re-verify what actually landed on disk, not just the staged copy.
         do {
-            try Self.runProcess(executable: "/usr/bin/open", arguments: ["-n", target.path])
+            try Self.verifySignature(of: target)
         } catch {
-            statusMessage = "The update was installed but Redline could not relaunch. Open it from Applications."
+            statusMessage = "The update was installed but failed verification."
             onChecked?()
             return
         }
-        NSApp.terminate(nil)
+
+        discardStaging()
+        availableUpdate = nil
+        relaunch(target: target)
+    }
+
+    /// Swaps `Redline.app.previous` back into place, verifying its signature first.
+    /// The just-replaced (newer) app becomes the new `.previous` — a revert is
+    /// itself reversible.
+    func revertToPrevious(target: URL = UpdateChecker.defaultInstallTarget) {
+        let targetDir = target.deletingLastPathComponent()
+        let previousURL = targetDir.appendingPathComponent("Redline.app.previous")
+
+        guard FileManager.default.fileExists(atPath: previousURL.path) else {
+            statusMessage = "No previous version to revert to."
+            onChecked?()
+            return
+        }
+
+        do {
+            try Self.verifySignature(of: previousURL)
+        } catch {
+            statusMessage = "The previous version failed verification and was not restored."
+            onChecked?()
+            return
+        }
+
+        do {
+            // `previousURL` cannot be handed to replaceItemAt directly: its own path
+            // IS the requested backup name, so the backup step would clobber it
+            // before the swap ever reads it. Stage a throwaway copy first, exactly
+            // like installStaged does for the forward direction.
+            let replacementDir = try FileManager.default.url(
+                for: .itemReplacementDirectory,
+                in: .userDomainMask,
+                appropriateFor: target,
+                create: true
+            )
+            defer { try? FileManager.default.removeItem(at: replacementDir) }
+
+            let newCopy = replacementDir.appendingPathComponent(target.lastPathComponent)
+            try Self.runProcess(executable: "/usr/bin/ditto", arguments: [previousURL.path, newCopy.path])
+            try FileManager.default.removeItem(at: previousURL)
+
+            _ = try FileManager.default.replaceItemAt(
+                target,
+                withItemAt: newCopy,
+                backupItemName: previousURL.lastPathComponent,
+                options: [.withoutDeletingBackupItem]
+            )
+        } catch {
+            statusMessage = "Could not revert to the previous version."
+            onChecked?()
+            return
+        }
+
+        relaunch(target: target)
+    }
+
+    /// The version recorded in `Redline.app.previous`'s Info.plist, or nil when no
+    /// rollback copy exists. Respects the snapshot-only override for panel rendering.
+    func previousVersion(target: URL = UpdateChecker.defaultInstallTarget) -> String? {
+        if snapshotUsesPreviousVersionOverride {
+            return snapshotPreviousVersionOverride
+        }
+        let previousURL = target.deletingLastPathComponent().appendingPathComponent("Redline.app.previous")
+        let plistURL = previousURL.appendingPathComponent("Contents/Info.plist")
+        guard let plist = NSDictionary(contentsOf: plistURL) as? [String: Any] else { return nil }
+        return plist["CFBundleShortVersionString"] as? String
     }
 
     static func resolvedAppcastURL() -> URL {
@@ -156,6 +282,67 @@ final class UpdateChecker {
         SHA256.hash(data: data).map { String(format: "%02x", $0) }.joined()
     }
 
+    /// Validates the code signature of the app at `appURL`: strictly, across all
+    /// architectures and nested code, then checks its bundle identifier and team
+    /// identifier against `expectedBundleIdentifier` / the allowed-teams set.
+    /// `REDLINE_ALLOWED_TEAMS` (comma separated) overrides the allowed set — for
+    /// the self-test only, so it can accept a locally re-signed fake bundle.
+    static func verifySignature(of appURL: URL) throws {
+        var staticCode: SecStaticCode?
+        let createStatus = SecStaticCodeCreateWithPath(appURL as CFURL, [], &staticCode)
+        guard createStatus == errSecSuccess, let code = staticCode else {
+            throw UpdateCheckError.signatureInvalid(
+                "could not read a code signature (status \(createStatus))"
+            )
+        }
+
+        let validityFlags = SecCSFlags(
+            rawValue: kSecCSStrictValidate | kSecCSCheckAllArchitectures | kSecCSCheckNestedCode
+        )
+        var validityError: Unmanaged<CFError>?
+        let validityStatus = SecStaticCodeCheckValidityWithErrors(code, validityFlags, nil, &validityError)
+        guard validityStatus == errSecSuccess else {
+            let detail = (validityError?.takeRetainedValue()).map { String(describing: $0) } ?? "status \(validityStatus)"
+            throw UpdateCheckError.signatureInvalid("signature is not valid: \(detail)")
+        }
+
+        var signingInfo: CFDictionary?
+        let infoStatus = SecCodeCopySigningInformation(
+            code,
+            SecCSFlags(rawValue: kSecCSSigningInformation),
+            &signingInfo
+        )
+        guard infoStatus == errSecSuccess, let info = signingInfo as? [String: Any] else {
+            throw UpdateCheckError.signatureInvalid("could not read signing information (status \(infoStatus))")
+        }
+
+        let identifier = info[kSecCodeInfoIdentifier as String] as? String
+        guard identifier == expectedBundleIdentifier else {
+            throw UpdateCheckError.signatureInvalid(
+                "unexpected bundle identifier: \(identifier ?? "nil")"
+            )
+        }
+
+        let teamIdentifier = info[kSecCodeInfoTeamIdentifier as String] as? String
+        guard let teamIdentifier, resolvedAllowedTeamIdentifiers().contains(teamIdentifier) else {
+            throw UpdateCheckError.signatureInvalid(
+                "unexpected team identifier: \(teamIdentifier ?? "nil")"
+            )
+        }
+    }
+
+    private static func resolvedAllowedTeamIdentifiers() -> Set<String> {
+        if let env = ProcessInfo.processInfo.environment["REDLINE_ALLOWED_TEAMS"], !env.isEmpty {
+            let parts = env.split(separator: ",")
+                .map { $0.trimmingCharacters(in: .whitespaces) }
+                .filter { !$0.isEmpty }
+            if !parts.isEmpty {
+                return Set(parts)
+            }
+        }
+        return allowedTeamIdentifiers
+    }
+
     // MARK: - Private
 
     private struct Appcast: Decodable {
@@ -170,10 +357,16 @@ final class UpdateChecker {
         case invalidPayload
         case httpStatus(Int)
         case processFailed(String)
+        case signatureInvalid(String)
     }
 
     private func fetchAppcast() async throws -> Appcast {
-        let data = try await fetchData(from: Self.resolvedAppcastURL())
+        let data: Data
+        if let testJSON = testAppcastJSON {
+            data = testJSON.data(using: .utf8) ?? Data()
+        } else {
+            data = try await fetchData(from: Self.resolvedAppcastURL())
+        }
         return try JSONDecoder().decode(Appcast.self, from: data)
     }
 
@@ -219,6 +412,7 @@ final class UpdateChecker {
         guard FileManager.default.fileExists(atPath: executable.path) else {
             throw UpdateCheckError.invalidPayload
         }
+        try Self.verifySignature(of: appURL)
         stagedAppURL = appURL
     }
 
@@ -235,6 +429,35 @@ final class UpdateChecker {
         stagedAppURL = nil
     }
 
+    /// Spawns a detached watcher that waits for this process to exit, then reopens
+    /// `target`, and quits. Never called during the self-test, so the in-process
+    /// assertions after `installStaged`/`revertToPrevious` can still run.
+    private func relaunch(target: URL) {
+        guard ProcessInfo.processInfo.environment["SHOTDECK_UPDATE_SELFTEST"] == nil else { return }
+
+        let ownPID = ProcessInfo.processInfo.processIdentifier
+        let script = "while kill -0 \(ownPID) 2>/dev/null; do sleep 0.2; done; " +
+            "/usr/bin/open -n \(Self.shellQuoted(target.path))"
+        let process = Process()
+        process.executableURL = URL(fileURLWithPath: "/bin/sh")
+        process.arguments = ["-c", script]
+        process.standardInput = FileHandle.nullDevice
+        process.standardOutput = FileHandle.nullDevice
+        process.standardError = FileHandle.nullDevice
+        do {
+            try process.run()
+        } catch {
+            statusMessage = "The update was installed but Redline could not relaunch. Open it from Applications."
+            onChecked?()
+            return
+        }
+        NSApp.terminate(nil)
+    }
+
+    private static func shellQuoted(_ path: String) -> String {
+        "'" + path.replacingOccurrences(of: "'", with: "'\\''") + "'"
+    }
+
     private static func findRedlineApp(in directory: URL) -> URL? {
         let fm = FileManager.default
         let direct = directory.appendingPathComponent("Redline.app")

Sources/Shotdeck/main.swift

@@ -24,8 +24,9 @@ struct ShotdeckApp: App {
                 .environment(appDelegate.model)
         } label: {
             let state = appDelegate.model.iconState
+            let hasUpdate = appDelegate.model.updateAvailable != nil
             HStack(spacing: 4) {
-                Image(systemName: state.symbolName)
+                menuBarIcon(for: state, hasUpdate: hasUpdate)
                 if let count = state.countText {
                     Text(count).font(.system(size: 11, weight: .semibold))
                 }
@@ -36,6 +37,29 @@ struct ShotdeckApp: App {
     }
 }
 
+/// The menu-bar symbol for `state`, badged while an update is staged. Uses the
+/// SF Symbol's own `.badge` variant when one exists; falls back to a small
+/// overlaid dot on the plain symbol otherwise. The badge disappears on its own
+/// once `updateAvailable` clears, since this reads live model state.
+@ViewBuilder
+private func menuBarIcon(for state: MenuIconState, hasUpdate: Bool) -> some View {
+    if hasUpdate {
+        let badgeName = "\(state.symbolName).badge"
+        if NSImage(systemSymbolName: badgeName, accessibilityDescription: nil) != nil {
+            Image(systemName: badgeName)
+        } else {
+            ZStack(alignment: .topTrailing) {
+                Image(systemName: state.symbolName)
+                Circle()
+                    .frame(width: 6, height: 6)
+                    .offset(x: 3, y: -3)
+            }
+        }
+    } else {
+        Image(systemName: state.symbolName)
+    }
+}
+
 @MainActor
 final class AppDelegate: NSObject, NSApplicationDelegate {
     let model: AppModel

Sources/ShotdeckCore/Support/DubaiTime.swift

@@ -3,6 +3,7 @@ import Foundation
 public enum DubaiTime {
     private static let stampFormatter = LockedDateFormatter(dateFormat: "d MMM yyyy, HH:mm 'Dubai'")
     private static let fileStampFormatter = LockedDateFormatter(dateFormat: "yyyyMMdd-HHmmss")
+    private static let checkTimeFormatter = LockedDateFormatter(dateFormat: "HH:mm 'Dubai'")
 
     public static func stamp(_ date: Date) -> String {
         stampFormatter.string(from: date)
@@ -11,6 +12,10 @@ public enum DubaiTime {
     public static func fileStamp(_ date: Date) -> String {
         fileStampFormatter.string(from: date)
     }
+
+    public static func checkTime(_ date: Date) -> String {
+        checkTimeFormatter.string(from: date)
+    }
 }
 
 /// DateFormatter is not Sendable. This holder is the only shared mutable state

Tests/ShotdeckTests/UpdateCheckerTests.swift

@@ -0,0 +1,118 @@
+import Foundation
+import Testing
+@testable import Shotdeck
+@testable import ShotdeckCore
+
+@Test("DubaiTime.checkTime formats as HH:MM Dubai")
+func dubaiTimeCheckTimeFormat() {
+    let now = Date()
+    let result = DubaiTime.checkTime(now)
+
+    // Dubai timezone format: HH:MM Dubai
+    let pattern = "^[0-9]{2}:[0-9]{2} Dubai$"
+    let regex = try? NSRegularExpression(pattern: pattern, options: [])
+    let range = NSRange(result.startIndex..<result.endIndex, in: result)
+    let matches = regex?.matches(in: result, options: [], range: range) ?? []
+    #expect(!matches.isEmpty, "checkTime should format as HH:MM Dubai, got: \(result)")
+}
+
+@Test("Status message: up-to-date manual check includes Dubai timestamp")
+@MainActor
+func manualCheckUpToDateIncludesTimestamp() async {
+    let checker = UpdateChecker()
+
+    // Inject a stub appcast showing the current version (no update available)
+    let currentVersion = UpdateChecker.currentVersion()
+    let stubAppcast = """
+    {
+      "version": "\(currentVersion)",
+      "zipURL": "https://example.com/dummy.zip",
+      "sha256": "0000000000000000000000000000000000000000000000000000000000000000"
+    }
+    """
+    checker.testAppcastJSON = stubAppcast
+
+    // Capture the status message
+    var capturedStatus: String?
+    checker.onChecked = {
+        capturedStatus = checker.statusMessage
+    }
+
+    // Run the manual check
+    await checker.checkNow(manual: true)
+
+    // Verify the message matches the expected format and includes a timestamp
+    guard let status = capturedStatus else {
+        #expect(false, "statusMessage should not be nil for manual check finding no update")
+        return
+    }
+
+    // Message should be "Redline X.Y.Z is up to date, checked HH:MM Dubai"
+    let pattern = "^Redline [0-9]+\\.[0-9]+\\.[0-9]+ is up to date, checked [0-9]{2}:[0-9]{2} Dubai$"
+    let regex = try? NSRegularExpression(pattern: pattern, options: [])
+    let range = NSRange(status.startIndex..<status.endIndex, in: status)
+    let matches = regex?.matches(in: status, options: [], range: range) ?? []
+    #expect(!matches.isEmpty, "Manual check up-to-date message should match format, got: \(status)")
+}
+
+@Test("Status message: automatic check doesn't set message when up-to-date")
+@MainActor
+func automaticCheckUpToDateLeavesMessageNil() async {
+    let checker = UpdateChecker()
+
+    // Inject a stub appcast showing the current version (no update available)
+    let currentVersion = UpdateChecker.currentVersion()
+    let stubAppcast = """
+    {
+      "version": "\(currentVersion)",
+      "zipURL": "https://example.com/dummy.zip",
+      "sha256": "0000000000000000000000000000000000000000000000000000000000000000"
+    }
+    """
+    checker.testAppcastJSON = stubAppcast
+
+    // Capture the status message
+    var capturedStatus: String?
+    checker.onChecked = {
+        capturedStatus = checker.statusMessage
+    }
+
+    // Run an AUTOMATIC check (manual: false)
+    await checker.checkNow(manual: false)
+
+    // For automatic checks finding no update, statusMessage should be nil
+    #expect(capturedStatus == nil,
+            "Automatic check finding no update should leave statusMessage nil, got: \(capturedStatus ?? "(nil)")")
+}
+
+@Test("Update status and general status are independent channels")
+@MainActor
+func statusChannelsAreIndependent() async throws {
+    let fm = FileManager.default
+    let appSupportRoot = fm.temporaryDirectory
+        .appendingPathComponent("update-checker-channel-test-\(UUID().uuidString)", isDirectory: true)
+    defer { try? fm.removeItem(at: appSupportRoot) }
+
+    // Create a real AppModel using the standard launch pattern
+    let model = AppDelegate.makeLaunchModel(appSupportRoot: appSupportRoot)
+    defer { model.hotkeys.unregisterAll() }
+
+    // Test 1: Setting statusLine should NOT affect updateStatusMessage
+    model.setStatus("General status: captured 3")
+    #expect(model.statusLine == "General status: captured 3", "statusLine should be set")
+    #expect(model.updateStatusMessage == nil, "updateStatusMessage should remain nil")
+
+    // Test 2: Setting updateStatus should NOT affect statusLine
+    model.setUpdateStatus("Update to 9.9.9 is ready")
+    #expect(model.statusLine == "General status: captured 3", "statusLine should remain unchanged")
+    #expect(model.updateStatusMessage == "Update to 9.9.9 is ready", "updateStatusMessage should be set")
+
+    // Test 3: Clearing statusLine leaves updateStatus intact
+    model.setStatus(nil)
+    #expect(model.statusLine == nil, "statusLine should be cleared")
+    #expect(model.updateStatusMessage == "Update to 9.9.9 is ready", "updateStatusMessage should persist")
+
+    // Test 4: Clearing updateStatus leaves other state unaffected
+    model.setUpdateStatus(nil)
+    #expect(model.updateStatusMessage == nil, "updateStatusMessage should be cleared")
+}

scripts/publish-update.sh

@@ -13,7 +13,10 @@ PLISTBUDDY="/usr/libexec/PlistBuddy"
 REMOTE_HOST="mmd01"
 REMOTE_BASE="/opt/mmd-installer-content/cowork/redline"
 PUBLIC_BASE="https://get.baobab-ts.com/cowork/redline"
-SIGN_IDENTITY="Apple Development: ben@flow-master.ai (QH2H9G2LK5)"
+BUNDLE_ID="ai.flowmaster.shotdeck"
+# Used both as the fallback signing identity and as what build-app.sh itself
+# still hardcodes for its own (pre-final) signing pass.
+FALLBACK_SIGN_IDENTITY="Apple Development: ben@flow-master.ai (QH2H9G2LK5)"
 
 usage() {
     echo "Usage: $0 <version> [\"notes\"]" >&2
@@ -72,6 +75,7 @@ else
     PUBLIC_DIR="${PUBLIC_BASE}"
 fi
 
+APP_BUNDLE="${ROOT}/.build/Redline.app"
 ZIP_NAME="Redline-${VERSION}.zip"
 DMG_NAME="Redline-${VERSION}.dmg"
 ZIP_PATH="${ROOT}/.build/${ZIP_NAME}"
@@ -139,6 +143,38 @@ else
     echo "==> --test: skipping git commit of version bump"
 fi
 
+# --- Resolve the signing identity for the shipped artifacts -----------------
+# REDLINE_KEYCHAIN (optional): a specific keychain to search/sign against,
+# for hosts where the Developer ID identity does not live in the login
+# keychain that codesign searches by default.
+FIND_IDENTITY_ARGS=(-v -p codesigning)
+CODESIGN_KEYCHAIN_ARGS=()
+if [[ -n "${REDLINE_KEYCHAIN:-}" ]]; then
+    FIND_IDENTITY_ARGS+=("${REDLINE_KEYCHAIN}")
+    CODESIGN_KEYCHAIN_ARGS=(--keychain "${REDLINE_KEYCHAIN}")
+fi
+
+if [[ -n "${REDLINE_SIGN_IDENTITY:-}" ]]; then
+    SIGN_IDENTITY="${REDLINE_SIGN_IDENTITY}"
+    echo "==> Signing identity: ${SIGN_IDENTITY} (REDLINE_SIGN_IDENTITY)"
+else
+    DEVELOPER_ID_LINE="$(security find-identity "${FIND_IDENTITY_ARGS[@]}" 2>/dev/null \
+        | grep -o '"Developer ID Application:[^"]*"' | head -n1 || true)"
+    DEVELOPER_ID="${DEVELOPER_ID_LINE//\"/}"
+    if [[ -n "${DEVELOPER_ID}" ]]; then
+        SIGN_IDENTITY="${DEVELOPER_ID}"
+        echo "==> Signing identity: ${SIGN_IDENTITY} (auto-detected Developer ID Application)"
+    else
+        SIGN_IDENTITY="${FALLBACK_SIGN_IDENTITY}"
+        echo
+        echo "************************************************************************"
+        echo "WARNING: signing with Apple Development identity — not Developer ID;"
+        echo "Gatekeeper will block first install on other Macs."
+        echo "************************************************************************"
+        echo
+    fi
+fi
+
 # Restricted HOMEs (agent sandboxes) hide the login keychain from codesign.
 # Re-run signed steps with the account's real home when the identity is missing.
 signing_home() {
@@ -167,31 +203,85 @@ run_signed() {
 echo "==> Building signed Redline.app"
 run_signed ./scripts/build-app.sh
 
-if [[ ! -d "${ROOT}/.build/Redline.app" ]]; then
-    echo "Signed app missing at ${ROOT}/.build/Redline.app" >&2
+if [[ ! -d "${APP_BUNDLE}" ]]; then
+    echo "Signed app missing at ${APP_BUNDLE}" >&2
     exit 1
 fi
 
-echo "==> Zipping Redline.app -> ${ZIP_PATH}"
+# build-app.sh always signs with its own hardcoded Apple Development identity
+# first (it has to — that identifier+identity pair is what keeps the Screen
+# Recording grant alive). Re-sign here with the identity actually resolved
+# above, which is what ships. A no-op when the two happen to be the same.
+echo "==> Signing ${APP_BUNDLE} with resolved identity"
+run_signed codesign --force --options runtime --timestamp \
+    ${CODESIGN_KEYCHAIN_ARGS[@]+"${CODESIGN_KEYCHAIN_ARGS[@]}"} \
+    --sign "${SIGN_IDENTITY}" \
+    --identifier "${BUNDLE_ID}" \
+    "${APP_BUNDLE}"
+
+build_zip() {
     mkdir -p "${ROOT}/.build"
     (
         cd "${ROOT}/.build"
         rm -f "${ZIP_NAME}"
         ditto -c -k --keepParent Redline.app "${ZIP_NAME}"
     )
-
     if [[ ! -s "${ZIP_PATH}" ]]; then
         echo "Zip was not created at ${ZIP_PATH}" >&2
         exit 1
     fi
+}
 
-echo "==> Building manual installer DMG"
-run_signed ./scripts/make-dmg.sh
+# Rebuilds the manual-installer DMG from whatever is currently at
+# ${APP_BUNDLE} — never re-invokes build-app.sh, so a prior custom signature
+# or notarization staple on ${APP_BUNDLE} survives into the DMG untouched.
+build_dmg() {
+    local staging="${ROOT}/.build/dmg-staging"
+    local mount_point="${ROOT}/.build/dmg-mnt"
 
+    rm -rf "${staging}"
+    mkdir -p "${staging}"
+    ditto "${APP_BUNDLE}" "${staging}/Redline.app"
+    ln -s /Applications "${staging}/Applications"
+
+    mkdir -p "$(dirname "${DMG_PATH}")"
+    rm -f "${DMG_PATH}"
+    hdiutil create -volname "Redline" -srcfolder "${staging}" -ov -format UDZO "${DMG_PATH}"
+
+    if [[ -d "${mount_point}" ]] && /sbin/mount | grep -F -q "${mount_point}"; then
+        hdiutil detach "${mount_point}" || hdiutil detach "${mount_point}" -force
+    fi
+    rm -rf "${mount_point}"
+    mkdir -p "${mount_point}"
+
+    hdiutil attach "${DMG_PATH}" -nobrowse -readonly -mountpoint "${mount_point}"
+
+    local ok=1
+    if [[ ! -d "${mount_point}/Redline.app" ]]; then
+        echo "Verification failed: Redline.app missing from mounted DMG" >&2
+        ok=0
+    fi
+    if [[ "${ok}" -eq 1 && "$(readlink "${mount_point}/Applications" 2>/dev/null || true)" != "/Applications" ]]; then
+        echo "Verification failed: Applications does not point at /Applications" >&2
+        ok=0
+    fi
+    if [[ "${ok}" -eq 1 ]] && ! codesign --verify --deep --verbose=2 "${mount_point}/Redline.app"; then
+        ok=0
+    fi
+
+    hdiutil detach "${mount_point}" || hdiutil detach "${mount_point}" -force || true
+
+    if [[ "${ok}" -ne 1 ]]; then
+        exit 1
+    fi
     if [[ ! -s "${DMG_PATH}" ]]; then
         echo "DMG was not created at ${DMG_PATH}" >&2
         exit 1
     fi
+}
+
+echo "==> Zipping Redline.app -> ${ZIP_PATH}"
+build_zip
 
 SHA256="$(shasum -a 256 "${ZIP_PATH}" | awk '{print $1}')"
 ZIP_BYTES="$(stat -f%z "${ZIP_PATH}")"
@@ -200,18 +290,102 @@ PUBDATE="$(date -u +"%Y-%m-%dT%H:%M:%SZ")"
 echo "==> Zip SHA256: ${SHA256}"
 echo "    Zip bytes:  ${ZIP_BYTES}"
 
+# --- Notarization (optional) -------------------------------------------------
+# Either REDLINE_NOTARY_PROFILE (a `notarytool store-credentials` keychain
+# profile) or all three of REDLINE_NOTARY_KEY_ID / REDLINE_NOTARY_ISSUER /
+# REDLINE_NOTARY_KEY_PATH (App Store Connect API key). Absent both: skip.
+NOTARIZED=0
+NOTARY_CONFIGURED=0
+if [[ -n "${REDLINE_NOTARY_PROFILE:-}" ]]; then
+    NOTARY_CONFIGURED=1
+elif [[ -n "${REDLINE_NOTARY_KEY_ID:-}" && -n "${REDLINE_NOTARY_ISSUER:-}" && -n "${REDLINE_NOTARY_KEY_PATH:-}" ]]; then
+    NOTARY_CONFIGURED=1
+fi
+
+if [[ "${NOTARY_CONFIGURED}" -eq 1 ]]; then
+    echo "==> Submitting ${ZIP_PATH} to notarytool"
+    NOTARY_ARGS=(xcrun notarytool submit "${ZIP_PATH}" --wait --timeout 30m)
+    if [[ -n "${REDLINE_NOTARY_PROFILE:-}" ]]; then
+        NOTARY_ARGS+=(--keychain-profile "${REDLINE_NOTARY_PROFILE}")
+    else
+        NOTARY_ARGS+=(
+            --key "${REDLINE_NOTARY_KEY_PATH}"
+            --key-id "${REDLINE_NOTARY_KEY_ID}"
+            --issuer "${REDLINE_NOTARY_ISSUER}"
+        )
+    fi
+
+    set +e
+    NOTARY_OUTPUT="$("${NOTARY_ARGS[@]}" 2>&1)"
+    NOTARY_STATUS=$?
+    set -e
+    echo "${NOTARY_OUTPUT}"
+    if [[ "${NOTARY_STATUS}" -ne 0 ]]; then
+        echo "notarytool submit failed (exit ${NOTARY_STATUS})." >&2
+        exit 1
+    fi
+    if ! grep -qi 'status: *Accepted' <<<"${NOTARY_OUTPUT}"; then
+        echo "notarytool did not report Accepted." >&2
+        exit 1
+    fi
+    NOTARIZED=1
+
+    echo "==> Stapling ${APP_BUNDLE}"
+    xcrun stapler staple "${APP_BUNDLE}"
+
+    echo "==> Rebuilding zip from the stapled app"
+    build_zip
+    SHA256="$(shasum -a 256 "${ZIP_PATH}" | awk '{print $1}')"
+    ZIP_BYTES="$(stat -f%z "${ZIP_PATH}")"
+    echo "    Zip SHA256: ${SHA256}"
+    echo "    Zip bytes:  ${ZIP_BYTES}"
+
+    echo "==> Rebuilding DMG from the stapled app"
+    build_dmg
+
+    echo "==> Stapling ${DMG_PATH}"
+    xcrun stapler staple "${DMG_PATH}"
+else
+    echo "==> REDLINE_NOTARY_KEY_ID/ISSUER/KEY_PATH (or REDLINE_NOTARY_PROFILE) not set"
+    echo "NOT NOTARIZED"
+    echo "==> Building manual installer DMG"
+    build_dmg
+fi
+
+echo "==> Gatekeeper check: spctl -a -vv -t exec ${APP_BUNDLE}"
+set +e
+SPCTL_OUTPUT="$(spctl -a -vv -t exec "${APP_BUNDLE}" 2>&1)"
+SPCTL_STATUS=$?
+set -e
+echo "${SPCTL_OUTPUT}"
+if [[ "${SPCTL_STATUS}" -ne 0 ]] || ! grep -qi 'accepted' <<<"${SPCTL_OUTPUT}"; then
+    if [[ "${NOTARIZED}" -eq 1 ]]; then
+        echo "spctl did not report accepted for ${APP_BUNDLE} although it was notarized." >&2
+        exit 1
+    fi
+    echo "WARNING: Gatekeeper does not accept this build (not notarized). First install on other Macs needs right-click > Open." >&2
+fi
+
+TEAM_IDENTIFIER="$(codesign -dv "${APP_BUNDLE}" 2>&1 | awk -F= '/^TeamIdentifier=/{print $2}')"
+if [[ -z "${TEAM_IDENTIFIER}" ]]; then
+    echo "No TeamIdentifier on ${APP_BUNDLE} — the build is not signed with a team identity; refusing to publish." >&2
+    exit 1
+fi
+
 echo "==> Writing ${APPCAST_PATH}"
-python3 - "${VERSION}" "${ZIP_URL}" "${SHA256}" "${NOTES}" "${PUBDATE}" "${APPCAST_PATH}" <<'PY'
+python3 - "${VERSION}" "${ZIP_URL}" "${SHA256}" "${NOTES}" "${PUBDATE}" "${APPCAST_PATH}" "${NOTARIZED}" "${TEAM_IDENTIFIER}" <<'PY'
 import json
 import sys
 
-version, zip_url, sha256, notes, pub_date, out_path = sys.argv[1:]
+version, zip_url, sha256, notes, pub_date, out_path, notarized, team_identifier = sys.argv[1:]
 payload = {
     "version": version,
     "zipURL": zip_url,
     "sha256": sha256,
     "notes": notes,
     "pubDate": pub_date,
+    "notarized": notarized == "1",
+    "teamIdentifier": team_identifier,
 }
 with open(out_path, "w", encoding="utf-8") as fh:
     json.dump(payload, fh, indent=2)
@@ -280,6 +454,14 @@ fi
 
 echo
 echo "Published v${VERSION}"
+echo "  identity:  ${SIGN_IDENTITY}"
+if [[ "${NOTARIZED}" -eq 1 ]]; then
+    echo "  notarized: yes"
+else
+    echo "  notarized: no"
+fi
+echo "  spctl:     ${SPCTL_OUTPUT}"
+echo "  team:      ${TEAM_IDENTIFIER}"
 echo "  appcast:   ${APPCAST_URL}"
 echo "  zip:       ${ZIP_URL}"
 echo "  sha256:    ${SHA256}"