feature: model-owned resolvedOneDriveFolder + OneDrive Settings/menu panel snapshots

SettingsView's OneDrive row called OneDriveLocator.resolveOneDriveFolder()
directly with the real UserDefaults.standard and the real home directory,
which made that row impossible to drive from a fake/isolated environment.
Moved that resolution into AppModel as a tracked resolvedOneDriveFolder
property (nil means "no OneDrive folder found"), refreshed at init,
bootstrap, chooseTransport, chooseOneDriveFolder, and inside send()'s live
folder check. SettingsView and chooseOneDriveFolder's picker-start path now
read model.resolvedOneDriveFolder instead of calling OneDriveLocator
directly — state flows through the model like everything else in this app.

PanelSnapshot (SHOTDECK_SNAPSHOT_DIR) adds three panels on a SEPARATE
isolated model so the transport switch never bleeds into the six existing
AirDrop-mode panels:
- panel-07-settings-onedrive.png: transport=oneDrive with a resolved folder,
  built by pointing OneDriveLocator.defaultRedlineFolder at a fake home tree
  (Library/CloudStorage/OneDrive-MMDGROUP under this snapshot's own temp
  root) so the displayed path is shaped like the real default without ever
  touching the real home.
- panel-08-settings-onedrive-missing.png: a fake home with no
  Library/CloudStorage at all, resolved through a throwaway UserDefaults
  suite (never .standard) so the "no OneDrive folder found" state and its
  still-usable Choose... button are exercised for real.
- panel-09-captures-present-onedrive.png: 3 captures + transport=oneDrive,
  confirming the menu row reads "Send to OneDrive".

Extracted the 3-swatch capture seeding (panel 04) into addSampleCaptures(to:)
so panel 09 reuses it instead of duplicating the loop.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012ZiTXPbPCSjzPVsfoweAbp

Sources/Shotdeck/AppModel.swift

@@ -32,6 +32,14 @@ public final class AppModel {
     public private(set) var isSending: Bool = false
     public private(set) var outboxDisplayName: String
     public private(set) var watchFolderDisplayName: String
+    /// Live transport choice; WP-onedrive reads this to pick the send path and to drive
+    /// the Settings "Send via" picker and the menu's "Send…" label.
+    public private(set) var transport: SendTransport
+    /// Ground truth for the Settings OneDrive row: nil means "no OneDrive folder found".
+    /// Views read this instead of calling `OneDriveLocator.resolveOneDriveFolder()`
+    /// directly, so state (and testing with a fake home) flows through the model like
+    /// everything else — never a View reaching past the model for real UserDefaults/home.
+    public private(set) var resolvedOneDriveFolder: URL?
     /// Live outbox; WP-4b reads this (not `paths.outbox`) so Settings folder changes take effect.
     public private(set) var outboxURL: URL
     /// Live watch folder; WP-4c updates this alongside `ReturnWatcher.updateWatchFolder`.
@@ -81,12 +89,16 @@ public final class AppModel {
         )
         self.region = Self.loadPersistedRegion()
         self.screenRecordingGranted = ScreenCapturer.isScreenRecordingGranted
-        // Seeded from FolderSettings.resolve() via resolvedAppSupportPaths — never .standard().
-        let folders = FolderSettings.resolve()
+        // Seeded from TransportSettings.effectiveFolders() — the one place that combines
+        // the transport choice with FolderSettings/OneDriveLocator. Never call
+        // FolderSettings.resolve() directly outside that function.
+        let folders = TransportSettings.effectiveFolders()
         self.outboxURL = folders.outbox
         self.watchFolderURL = folders.watch
         self.outboxDisplayName = folders.outbox.lastPathComponent
         self.watchFolderDisplayName = folders.watch.lastPathComponent
+        self.transport = folders.transport
+        self.resolvedOneDriveFolder = OneDriveLocator.resolveOneDriveFolder()
         self.captureHotkey = HotkeyPreference.load()
         self.updateChecker = UpdateChecker()
         self.updateChecker.onChecked = { [weak self] in
@@ -118,6 +130,8 @@ public final class AppModel {
         watchFolderURL = watch
         setFolderDisplayNames(outbox: outbox.lastPathComponent, watch: watch.lastPathComponent)
     }
+    func setTransport(_ value: SendTransport) { transport = value }
+    func setResolvedOneDriveFolder(_ value: URL?) { resolvedOneDriveFolder = value }
     func rememberLastComposedPDF(_ url: URL) { lastComposedPDFURL = url }
 
     /// True when a last-composed PDF path is known this run, or the newest
@@ -185,6 +199,17 @@ public final class AppModel {
             // Empty ledger on first run is not an error.
         }
 
+        // OneDrive mode: outbox == watch folder, so a freshly written, unmarked PDF must
+        // never show up as a return; only a document that already carries a mark does.
+        // Also make sure the resolved OneDrive folder actually exists before the
+        // watcher starts watching it (bootstrap is the other creation trigger besides
+        // chooseTransport/chooseOneDriveFolder — see TransportSettings.effectiveFolders).
+        if transport == .oneDrive {
+            try? FileManager.default.createDirectory(at: outboxURL, withIntermediateDirectories: true)
+        }
+        setResolvedOneDriveFolder(OneDriveLocator.resolveOneDriveFolder())
+        await watcher.setRecordUncommented(transport == .airDrop)
+
         do {
             try await watcher.start { [weak self] _ in
                 Task { @MainActor in
@@ -208,6 +233,8 @@ public final class AppModel {
             ProcessInfo.processInfo.environment["SHOTDECK_PICKER_SELFTEST"] != nil
             || ProcessInfo.processInfo.environment["SHOTDECK_SNAPSHOT_DIR"] != nil
             || ProcessInfo.processInfo.environment["SHOTDECK_UPDATE_SELFTEST"] != nil
+            || ProcessInfo.processInfo.environment["SHOTDECK_ONEDRIVE_SELFTEST"] != nil
+            || ProcessInfo.processInfo.environment["REDLINE_SELFTEST_PHASE"] != nil
         if !skipSchedule {
             updateChecker.startSchedule()
         }

Sources/Shotdeck/MenuBarView.swift

@@ -91,7 +91,7 @@ struct MenuBarView: View {
                     model.setStatus("Send is not available in this build.")
                 }
             } label: {
-                actionLabel("Send…")
+                actionLabel(model.transport == .oneDrive ? "Send to OneDrive" : "Send…")
             }
             .disabled(model.session.isEmpty || model.isSending)
 

Sources/Shotdeck/PanelSnapshot.swift

@@ -61,6 +61,28 @@ enum PanelSnapshot {
         try renderMenuBar(model: model, to: directory, name: "03-empty-session")
 
         // 04 — three real PNGs in the temp spool so SessionStrip thumbnails decode.
+        try await addSampleCaptures(to: model)
+        try renderMenuBar(model: model, to: directory, name: "04-captures-present")
+
+        // 05 — two inspected PDFs in the temp ledger, one marked / one not.
+        try await seedReturns(model: model)
+        try renderMenuBar(model: model, to: directory, name: "05-returns-present")
+
+        // 06 — SettingsView against the same isolated model.
+        try render(
+            SettingsView().environment(model),
+            to: directory.appendingPathComponent("panel-06-settings.png")
+        )
+
+        // 07/08/09 — OneDrive-mode Settings + menu bar, on a SEPARATE isolated model so
+        // this transport switch never bleeds into the AirDrop-mode panels above.
+        try await captureOneDrivePanels(to: directory)
+    }
+
+    /// Three real PNGs appended to the given model's temp spool so SessionStrip
+    /// thumbnails decode. Shared by panel 04 (AirDrop) and panel 09 (OneDrive).
+    @MainActor
+    private static func addSampleCaptures(to model: AppModel) async throws {
         let swatches: [(CGFloat, CGFloat, CGFloat)] = [
             (0.85, 0.22, 0.18),
             (0.18, 0.62, 0.32),
@@ -77,17 +99,62 @@ enum PanelSnapshot {
             )
         }
         model.replaceSession(try await model.spool.currentSession())
-        try renderMenuBar(model: model, to: directory, name: "04-captures-present")
+    }
 
-        // 05 — two inspected PDFs in the temp ledger, one marked / one not.
-        try await seedReturns(model: model)
-        try renderMenuBar(model: model, to: directory, name: "05-returns-present")
+    /// Panels 07-09: OneDrive transport, on its own isolated model/temp root so
+    /// switching transport here never touches the AirDrop-mode model above, the real
+    /// home directory, or UserDefaults.standard. The "resolved" and "not found" states
+    /// are produced by calling the real OneDriveLocator functions against fake home
+    /// trees built under this snapshot's own temp root — never a hand-typed path.
+    @MainActor
+    private static func captureOneDrivePanels(to directory: URL) async throws {
+        let (model, root) = try makeIsolatedModel()
+        defer { try? FileManager.default.removeItem(at: root) }
+        model.setTransport(.oneDrive)
 
-        // 06 — SettingsView against the same isolated model.
+        // 07 — a resolved OneDrive folder, shaped like the real default
+        // (…/Library/CloudStorage/OneDrive-MMDGROUP/Redline): a fake home tree with a
+        // real OneDrive-MMDGROUP directory under it, resolved via the same pure
+        // OneDriveLocator function production code uses — never a hand-typed path.
+        let fakeHomeWithOneDrive = root.appendingPathComponent("fake-home-with-onedrive", isDirectory: true)
+        let syncRoot = fakeHomeWithOneDrive
+            .appendingPathComponent("Library/CloudStorage/OneDrive-MMDGROUP", isDirectory: true)
+        try FileManager.default.createDirectory(at: syncRoot, withIntermediateDirectories: true)
+        guard let resolvedFolder = OneDriveLocator.defaultRedlineFolder(
+            home: fakeHomeWithOneDrive, fileManager: .default
+        ) else {
+            throw SnapshotError.oneDriveFixtureFailed("fake OneDrive-MMDGROUP root did not resolve")
+        }
+        model.setResolvedOneDriveFolder(resolvedFolder)
         try render(
             SettingsView().environment(model),
-            to: directory.appendingPathComponent("panel-06-settings.png")
+            to: directory.appendingPathComponent("panel-07-settings-onedrive.png")
         )
+
+        // 08 — no OneDrive folder found: a fake home with NO Library/CloudStorage at
+        // all, and a throwaway UserDefaults suite (never .standard, never touched
+        // before) so the stored-override check also legitimately finds nothing.
+        let fakeHomeWithoutOneDrive = root.appendingPathComponent("fake-home-without-onedrive", isDirectory: true)
+        try FileManager.default.createDirectory(at: fakeHomeWithoutOneDrive, withIntermediateDirectories: true)
+        let isolatedDefaults = try makeIsolatedDefaultsSuite()
+        defer { isolatedDefaults.defaults.removePersistentDomain(forName: isolatedDefaults.suiteName) }
+        let missingFolder = OneDriveLocator.resolveOneDriveFolder(
+            defaults: isolatedDefaults.defaults, home: fakeHomeWithoutOneDrive, fileManager: .default
+        )
+        guard missingFolder == nil else {
+            throw SnapshotError.oneDriveFixtureFailed("fake home without OneDrive unexpectedly resolved")
+        }
+        model.setResolvedOneDriveFolder(nil)
+        try render(
+            SettingsView().environment(model),
+            to: directory.appendingPathComponent("panel-08-settings-onedrive-missing.png")
+        )
+
+        // 09 — menu bar panel, 3 captures present, OneDrive mode ("Send to OneDrive").
+        model.snapshotSetScreenRecordingGranted(true)
+        model.replaceRegion(sampleRegion())
+        try await addSampleCaptures(to: model)
+        try renderMenuBar(model: model, to: directory, name: "09-captures-present-onedrive")
     }
 
     @MainActor
@@ -177,6 +244,23 @@ enum PanelSnapshot {
         return (model, root)
     }
 
+    /// A throwaway UserDefaults suite — never `.standard` — for the panel-08 fixture,
+    /// the same isolation pattern ShotdeckCoreTests uses for TransportSettings/
+    /// OneDriveLocator tests.
+    private struct IsolatedDefaultsSuite {
+        let suiteName: String
+        let defaults: UserDefaults
+    }
+
+    private static func makeIsolatedDefaultsSuite() throws -> IsolatedDefaultsSuite {
+        let suiteName = "shotdeck-panel-snapshot-\(UUID().uuidString)"
+        guard let defaults = UserDefaults(suiteName: suiteName) else {
+            throw SnapshotError.oneDriveFixtureFailed("could not create isolated UserDefaults suite")
+        }
+        defaults.removePersistentDomain(forName: suiteName)
+        return IsolatedDefaultsSuite(suiteName: suiteName, defaults: defaults)
+    }
+
     @MainActor
     private static func seedReturns(model: AppModel) async throws {
         let watch = model.paths.watchFolder
@@ -283,6 +367,7 @@ private enum SnapshotError: Error, CustomStringConvertible {
     case encodeFailed(String)
     case pngGenerationFailed
     case pdfWriteFailed(String)
+    case oneDriveFixtureFailed(String)
 
     var description: String {
         switch self {
@@ -290,6 +375,7 @@ private enum SnapshotError: Error, CustomStringConvertible {
         case .encodeFailed(let name): return "PNG encode failed for \(name)"
         case .pngGenerationFailed: return "CoreGraphics PNG generation failed"
         case .pdfWriteFailed(let name): return "could not write \(name)"
+        case .oneDriveFixtureFailed(let detail): return "OneDrive snapshot fixture failed: \(detail)"
         }
     }
 }

Sources/Shotdeck/PickerSelfTest.swift

@@ -3,6 +3,7 @@ import CoreGraphics
 import Darwin
 import Foundation
 import ImageIO
+import PDFKit
 import ShotdeckCore
 
 /// In-process self-test for the region picker, driven by `SHOTDECK_PICKER_SELFTEST`.
@@ -173,7 +174,7 @@ enum PickerSelfTest {
                 try await executeSendTruth()
                 print("SEND-TRUTH PASS")
                 fflush(stdout)
-                if !startUpdateSelfTestIfRequested() {
+                if !startUpdateSelfTestIfRequested(), !startOneDriveSelfTestIfRequested() {
                     exit(0)
                 }
             } catch {
@@ -315,7 +316,9 @@ enum PickerSelfTest {
                 try await runUpdateSelfTest(outputDirectory: output)
                 print("UPDATE-SELFTEST PASS version=99.0.0")
                 fflush(stdout)
+                if !startOneDriveSelfTestIfRequested() {
                     exit(0)
+                }
             } catch let error as UpdateSelfTestError {
                 updateFail(error.description)
             } catch {
@@ -473,6 +476,194 @@ enum PickerSelfTest {
         exit(1)
     }
 
+    /// Real sync root this Mac has; the phase proves the transport against the actual
+    /// OneDrive file provider, never a fake home tree (that is what
+    /// OneDriveLocatorTests in ShotdeckCoreTests are for).
+    private static let realOneDriveSyncRoot = URL(
+        fileURLWithPath: "/Users/benjaminhippler/Library/CloudStorage/OneDrive-MMDGROUP",
+        isDirectory: true
+    )
+
+    /// Phase 5: proves the OneDrive transport end to end against the real sync root.
+    /// Triggered by `SHOTDECK_ONEDRIVE_SELFTEST` when chained after PICKER/SEND-TRUTH/
+    /// UPDATE-SELFTEST — the exact pattern `startUpdateSelfTestIfRequested` uses for its
+    /// own env var. Returns true when the async phase was scheduled (it calls `exit` itself).
+    @discardableResult
+    private static func startOneDriveSelfTestIfRequested() -> Bool {
+        guard ProcessInfo.processInfo.environment["SHOTDECK_ONEDRIVE_SELFTEST"] != nil else {
+            return false
+        }
+        runOneDriveSelfTestAndExit()
+        return true
+    }
+
+    /// Entry point for running ONLY this phase, bypassing the on-screen picker chain
+    /// entirely. The harness has no other per-phase selector, so this is the escape
+    /// hatch: `REDLINE_SELFTEST_PHASE=onedrive`.
+    static func runOneDriveOnlyIfRequested() {
+        guard ProcessInfo.processInfo.environment["REDLINE_SELFTEST_PHASE"] == "onedrive" else {
+            return
+        }
+        // Same hop as runIfRequested(): a plain main-queue turn after NSApp starts, so
+        // AppKit/PDFKit calls inside the phase are not racing app launch.
+        DispatchQueue.main.async {
+            MainActor.assumeIsolated {
+                runOneDriveSelfTestAndExit()
+            }
+        }
+    }
+
+    private static func runOneDriveSelfTestAndExit() {
+        Task { @MainActor in
+            do {
+                let folder = try await executeOneDriveSelfTest()
+                print("ONEDRIVE-SELFTEST PASS path=\(folder.path)")
+                fflush(stdout)
+                exit(0)
+            } catch let error as OneDriveSelfTestError {
+                oneDriveFail(error.description)
+            } catch {
+                oneDriveFail(String(describing: error))
+            }
+        }
+    }
+
+    /// Builds a session, sends it through the OneDrive branch of `send(anchor: nil)`
+    /// against a NEW folder under the real OneDrive sync root, confirms the watcher does
+    /// NOT report the freshly-written unmarked PDF as a return, then adds a real PDFKit
+    /// ink annotation in place (what the iPad does) and confirms the watcher now reports
+    /// it as commented. Never deletes anything under OneDrive — the created folder and
+    /// PDF are left in place for Ben to inspect / for the real iPad round trip.
+    private static func executeOneDriveSelfTest() async throws -> URL {
+        let fm = FileManager.default
+        guard fm.fileExists(atPath: realOneDriveSyncRoot.path) else {
+            throw OneDriveSelfTestError.detail(
+                "real OneDrive sync root not found at \(realOneDriveSyncRoot.path)"
+            )
+        }
+
+        // UserDefaults.standard is the ONLY defaults instance send()/TransportSettings
+        // actually read at runtime (there is no defaults-threading through AppModel), so
+        // "isolated" here means snapshot-and-restore around the real keys — the same
+        // pattern runRegionPersistPhase already uses for CaptureRegion.defaultsKey.
+        let defaults = UserDefaults.standard
+        let previousTransport = defaults.string(forKey: TransportSettings.transportDefaultsKey)
+        let previousFolder = defaults.string(forKey: TransportSettings.oneDriveFolderDefaultsKey)
+        defer {
+            if let previousTransport {
+                defaults.set(previousTransport, forKey: TransportSettings.transportDefaultsKey)
+            } else {
+                defaults.removeObject(forKey: TransportSettings.transportDefaultsKey)
+            }
+            if let previousFolder {
+                defaults.set(previousFolder, forKey: TransportSettings.oneDriveFolderDefaultsKey)
+            } else {
+                defaults.removeObject(forKey: TransportSettings.oneDriveFolderDefaultsKey)
+            }
+        }
+
+        let stamp = DubaiTime.fileStamp(Date())
+        let selftestFolder = realOneDriveSyncRoot
+            .appendingPathComponent("Redline-selftest-\(stamp)", isDirectory: true)
+        try fm.createDirectory(at: selftestFolder, withIntermediateDirectories: true)
+
+        TransportSettings.setTransport(.oneDrive, defaults: defaults)
+        TransportSettings.setOneDriveFolder(selftestFolder, defaults: defaults)
+
+        // Local spool root only — the outbox/watch folder is the real OneDrive folder.
+        let spoolRoot = fm.temporaryDirectory
+            .appendingPathComponent("shotdeck-onedrive-selftest-\(UUID().uuidString)", isDirectory: true)
+        defer { try? fm.removeItem(at: spoolRoot) }
+
+        let paths = try AppSupportPaths(root: spoolRoot, outbox: selftestFolder, watchFolder: selftestFolder)
+        let ledger = try ReturnLedger(paths: paths)
+        let watcher = ReturnWatcher(paths: paths, ledger: ledger)
+        await watcher.setRecordUncommented(false)   // OneDrive mode: today's default is AirDrop's `true`.
+
+        let model = AppModel(
+            paths: paths,
+            spool: try SpoolStore(paths: paths),
+            composer: PDFComposer(),
+            capturer: ScreenCapturer(),
+            hotkeys: HotkeyCenter(),
+            picker: RegionPickerController(),
+            ledger: ledger,
+            watcher: watcher
+        )
+        model.setFolderURLs(outbox: selftestFolder, watch: selftestFolder)
+        model.setTransport(.oneDrive)
+
+        let png = try makeTinyPNGData()
+        _ = try await model.spool.append(
+            pngData: png, pixelWidth: 64, pixelHeight: 48, scale: 1, capturedAt: Date()
+        )
+        model.replaceSession(try await model.spool.currentSession())
+        guard !model.session.isEmpty else {
+            throw OneDriveSelfTestError.detail("seeded session was empty")
+        }
+
+        await model.send(anchor: nil)
+
+        guard let status = model.statusLine, status.hasPrefix("Saved to OneDrive") else {
+            throw OneDriveSelfTestError.detail(
+                "status did not start with 'Saved to OneDrive': \(model.statusLine ?? "nil")"
+            )
+        }
+        guard model.session.isEmpty else {
+            throw OneDriveSelfTestError.detail("session was not archived after the OneDrive send")
+        }
+
+        let written = (try? fm.contentsOfDirectory(at: selftestFolder, includingPropertiesForKeys: nil)) ?? []
+        guard let pdfURL = written.first(where: { $0.pathExtension.lowercased() == "pdf" }) else {
+            throw OneDriveSelfTestError.detail("no PDF found in \(selftestFolder.path)")
+        }
+
+        // Unmarked so far: the watcher must not treat it as a return.
+        let beforeMarkup = try await watcher.scanNow()
+        guard !beforeMarkup.contains(where: { $0.fileURL == pdfURL }) else {
+            throw OneDriveSelfTestError.detail("unmarked PDF was reported as returned by scanNow")
+        }
+        let commentedBefore = try await ledger.commented()
+        guard !commentedBefore.contains(where: { $0.fileURL == pdfURL }) else {
+            throw OneDriveSelfTestError.detail("unmarked PDF was recorded as commented in the ledger")
+        }
+
+        // What the iPad does: mark it up in place with a real ink annotation, then save.
+        guard let document = PDFDocument(url: pdfURL), let page = document.page(at: 0) else {
+            throw OneDriveSelfTestError.detail("could not reopen \(pdfURL.path) to annotate it")
+        }
+        let ink = PDFAnnotation(
+            bounds: CGRect(x: 20, y: 20, width: 60, height: 60),
+            forType: .ink,
+            withProperties: nil
+        )
+        let stroke = NSBezierPath()
+        stroke.move(to: NSPoint(x: 20, y: 20))
+        stroke.line(to: NSPoint(x: 80, y: 80))
+        ink.add(stroke)
+        page.addAnnotation(ink)
+        guard document.write(to: pdfURL) else {
+            throw OneDriveSelfTestError.detail("could not save the annotated PDF back to \(pdfURL.path)")
+        }
+
+        let afterMarkup = try await watcher.scanNow()
+        guard let recorded = afterMarkup.first(where: { $0.fileURL == pdfURL }), recorded.isCommented else {
+            throw OneDriveSelfTestError.detail("annotated PDF was not reported as commented by scanNow")
+        }
+        let commentedAfter = try await ledger.commented()
+        guard commentedAfter.contains(where: { $0.fileURL == pdfURL }) else {
+            throw OneDriveSelfTestError.detail("annotated PDF was not recorded in the ledger as commented")
+        }
+
+        return selftestFolder
+    }
+
+    private static func oneDriveFail(_ detail: String) -> Never {
+        print("ONEDRIVE-SELFTEST FAIL \(detail)")
+        fflush(stdout)
+        exit(1)
+    }
+
     private static func interpolate(_ step: Int) -> NSPoint {
         let t = CGFloat(step) / CGFloat(dragSteps)
         return NSPoint(
@@ -538,3 +729,12 @@ private enum UpdateSelfTestError: Error, CustomStringConvertible {
         }
     }
 }
+
+private enum OneDriveSelfTestError: Error, CustomStringConvertible {
+    case detail(String)
+    var description: String {
+        switch self {
+        case .detail(let s): return s
+        }
+    }
+}

Sources/Shotdeck/SendController.swift

@@ -16,6 +16,33 @@ extension AppModel: SendCapable {
         guard !session.isEmpty, !isSending else { return }
         setSending(true)
 
+        let transport = TransportSettings.transport()
+
+        // OneDrive mode: verify the real destination exists RIGHT NOW, before composing
+        // anything. `outboxURL` is kept in sync with the resolved OneDrive folder by
+        // bootstrap/chooseTransport/chooseOneDriveFolder, but this is re-resolved fresh
+        // here (never trusted stale) so a folder that vanished since then (OneDrive
+        // signed out, external volume unmounted, folder deleted) is caught instead of
+        // silently writing into whatever `outboxURL` happens to hold.
+        if transport == .oneDrive {
+            guard let folder = OneDriveLocator.resolveOneDriveFolder(),
+                  Self.directoryExists(at: folder)
+            else {
+                let path = OneDriveLocator.resolveOneDriveFolder()?.path
+                    ?? TransportSettings.storedOneDriveFolderPath()
+                    ?? "no OneDrive folder found"
+                setResolvedOneDriveFolder(nil)
+                setStatus(ShotdeckError.oneDriveFolderUnavailable(path: path).errorDescription)
+                setSending(false)
+                return
+            }
+            setResolvedOneDriveFolder(folder)
+            if outboxURL != folder || watchFolderURL != folder {
+                setFolderURLs(outbox: folder, watch: folder)
+                try? await watcher.updateWatchFolder(folder)
+            }
+        }
+
         let pending: ComposedSend
         do {
             pending = try await composePDFForSend()
@@ -27,6 +54,18 @@ extension AppModel: SendCapable {
             return
         }
 
+        switch transport {
+        case .oneDrive:
+            // No AirDrop, no anchor needed — the PDF is already in the watched
+            // OneDrive folder. Archive immediately; the iPad marks it up in place.
+            await handleDidShareItems(fileName: pending.fileName, pageCount: pending.pageCount)
+            let pageWord = pending.pageCount == 1 ? "page" : "pages"
+            setStatus(
+                "Saved to OneDrive — \(pending.pageCount) \(pageWord). Open it in Files on your iPad."
+            )
+            setSending(false)
+
+        case .airDrop:
             guard let anchor else {
                 handleDidFailToShareItems(fileName: pending.fileName)
                 setSending(false)
@@ -52,6 +91,13 @@ extension AppModel: SendCapable {
                 setSending(false)
             }
         }
+    }
+
+    private static func directoryExists(at url: URL) -> Bool {
+        var isDirectory: ObjCBool = false
+        let exists = FileManager.default.fileExists(atPath: url.path, isDirectory: &isDirectory)
+        return exists && isDirectory.boolValue
+    }
 
     /// Writes the PDF to the outbox and records its path. Does not archive the session
     /// and does not present AirDrop — that happens only after the share completes.

Sources/Shotdeck/SettingsView.swift

@@ -33,6 +33,25 @@ struct SettingsView: View {
                 .frame(minHeight: 22)
             }
 
+            GridRow {
+                Text("Send via")
+                    .font(.headline)
+                    .frame(maxWidth: .infinity, alignment: .leading)
+                    .gridCellColumns(2)
+                    .padding(.top, 6)
+            }
+
+            GridRow {
+                Picker("Send via", selection: transportBinding) {
+                    ForEach(SendTransport.allCases, id: \.self) { transport in
+                        Text(transport.displayName).tag(transport)
+                    }
+                }
+                .labelsHidden()
+                .pickerStyle(.segmented)
+                .gridCellColumns(2)
+            }
+
             GridRow {
                 Text("Folders")
                     .font(.headline)
@@ -41,6 +60,7 @@ struct SettingsView: View {
                     .padding(.top, 6)
             }
 
+            if model.transport == .airDrop {
                 GridRow(alignment: .center) {
                     fieldLabel("Watch folder")
                     folderValue(path: model.watchFolderURL.path) {
@@ -54,6 +74,36 @@ struct SettingsView: View {
                         model.chooseOutboxFolder()
                     }
                 }
+            } else {
+                GridRow(alignment: .center) {
+                    fieldLabel("OneDrive folder")
+                    if let folder = model.resolvedOneDriveFolder {
+                        folderValue(path: folder.path) {
+                            model.chooseOneDriveFolder()
+                        }
+                    } else {
+                        HStack(spacing: 8) {
+                            Text("No OneDrive folder found — sign in to OneDrive or choose a folder.")
+                                .font(.caption)
+                                .foregroundStyle(.secondary)
+                                .fixedSize(horizontal: false, vertical: true)
+                                .frame(maxWidth: .infinity, alignment: .leading)
+                            Button("Choose…") { model.chooseOneDriveFolder() }
+                        }
+                        .frame(minHeight: 22)
+                    }
+                }
+
+                GridRow {
+                    Text(
+                        "The PDF is saved here and this same folder is watched for the marked-up copy. On the iPad open it from Files > OneDrive."
+                    )
+                    .font(.caption)
+                    .foregroundStyle(.secondary)
+                    .fixedSize(horizontal: false, vertical: true)
+                    .gridCellColumns(2)
+                }
+            }
 
             GridRow {
                 Button("Reveal spool folder") { model.openSpoolFolder() }
@@ -68,6 +118,10 @@ struct SettingsView: View {
         .onDisappear { disarmHotkeyRecorder() }
     }
 
+    private var transportBinding: Binding<SendTransport> {
+        Binding(get: { model.transport }, set: { model.chooseTransport($0) })
+    }
+
     private func armHotkeyRecorder() {
         guard !isRecordingHotkey else { return }
         isRecordingHotkey = true
@@ -190,6 +244,55 @@ extension AppModel: SettingsWindowPresenting {
         }
     }
 
+    /// Settings "Send via" picker action. Persists the choice, recomputes the effective
+    /// outbox/watch folder for the new transport, creates the OneDrive folder if it
+    /// doesn't exist yet, and re-points the running watcher (folder + recordUncommented)
+    /// at the new state. Switching back to AirDrop restores its own stored overrides
+    /// untouched, since AirDrop and OneDrive folder settings are stored under separate keys.
+    func chooseTransport(_ value: SendTransport) {
+        guard value != transport else { return }
+        TransportSettings.setTransport(value)
+        setTransport(value)
+        let folders = TransportSettings.effectiveFolders()
+        if value == .oneDrive {
+            try? FileManager.default.createDirectory(
+                at: folders.outbox, withIntermediateDirectories: true
+            )
+        }
+        setFolderURLs(outbox: folders.outbox, watch: folders.watch)
+        setResolvedOneDriveFolder(OneDriveLocator.resolveOneDriveFolder())
+        Task {
+            await watcher.setRecordUncommented(value == .airDrop)
+            do {
+                try await watcher.updateWatchFolder(folders.watch)
+            } catch {
+                setStatus(
+                    (error as? ShotdeckError)?.errorDescription ?? "Could not switch the watch folder."
+                )
+            }
+        }
+    }
+
+    func chooseOneDriveFolder() {
+        let start = resolvedOneDriveFolder ?? FileManager.default.homeDirectoryForCurrentUser
+        guard let url = chooseDirectory(startingAt: start) else { return }
+        TransportSettings.setOneDriveFolder(url)
+        try? FileManager.default.createDirectory(at: url, withIntermediateDirectories: true)
+        setResolvedOneDriveFolder(OneDriveLocator.resolveOneDriveFolder())
+        guard transport == .oneDrive else { return }
+        setFolderURLs(outbox: url, watch: url)
+        Task {
+            do {
+                try await watcher.updateWatchFolder(url)
+                setStatus("OneDrive folder set to \(url.lastPathComponent).")
+            } catch {
+                setStatus(
+                    (error as? ShotdeckError)?.errorDescription ?? "Could not switch the watch folder."
+                )
+            }
+        }
+    }
+
     private func chooseDirectory(startingAt directory: URL) -> URL? {
         let panel = NSOpenPanel()
         panel.canChooseDirectories = true

Sources/Shotdeck/main.swift

@@ -7,6 +7,9 @@ import ShotdeckCore
 if ProcessInfo.processInfo.environment["SHOTDECK_SNAPSHOT_DIR"] != nil {
     MainActor.assumeIsolated { PanelSnapshot.runIfRequested() }
 }
+if ProcessInfo.processInfo.environment["REDLINE_SELFTEST_PHASE"] == "onedrive" {
+    MainActor.assumeIsolated { PickerSelfTest.runOneDriveOnlyIfRequested() }
+}
 if ProcessInfo.processInfo.environment["SHOTDECK_PICKER_SELFTEST"] != nil {
     MainActor.assumeIsolated { PickerSelfTest.runIfRequested() }
 }

Sources/ShotdeckCore/Model/ShotdeckError.swift

@@ -10,6 +10,7 @@ public enum ShotdeckError: Error, LocalizedError, Sendable {
     case pdfCompositionFailed(reason: String)
     case airDropUnavailable
     case noCommentedReturns
+    case oneDriveFolderUnavailable(path: String)
 
     public var errorDescription: String? {
         switch self {
@@ -31,6 +32,8 @@ public enum ShotdeckError: Error, LocalizedError, Sendable {
             return "AirDrop is not available right now."
         case .noCommentedReturns:
             return "None of the returned PDFs have comments on them."
+        case .oneDriveFolderUnavailable(let path):
+            return "Your OneDrive folder is not available: \(path). Check that OneDrive is signed in, or choose another folder in Settings."
         }
     }
 }

Sources/ShotdeckCore/Returns/ReturnWatcher.swift

@@ -10,6 +10,12 @@ public actor ReturnWatcher {
     private var bridge: FSEventBridge?
     private var pendingScanTask: Task<Void, Never>?
     private let eventQueue = DispatchQueue(label: "ai.flowmaster.shotdeck.returns.fsevents")
+    /// When false, a document with zero human marks is neither recorded into the ledger
+    /// nor included in scanNow's/onChange's results — needed for OneDrive mode, where the
+    /// outbox and watch folder are the same folder and a freshly written, unmarked PDF
+    /// must not be treated as a return. Defaults to true (today's AirDrop behaviour).
+    /// A document that IS commented is always recorded, regardless of this flag.
+    public var recordUncommented: Bool = true
 
     /// Watch folder is `paths.watchFolder`, which production constructs from
     /// `FolderSettings.resolve().watch`. This type never calls FolderSettings;
@@ -29,6 +35,12 @@ public actor ReturnWatcher {
         onChange(found)
     }
 
+    /// Sets `recordUncommented`. A `func` (not a plain property set) only because
+    /// callers outside this actor must `await` it like any other actor mutation.
+    public func setRecordUncommented(_ value: Bool) {
+        recordUncommented = value
+    }
+
     /// Idempotent. Stops and releases the FSEventStream if one is running; safe to call
     /// when never started or already stopped. Cancels any pending debounced scan.
     public func stop() {
@@ -77,6 +89,7 @@ public actor ReturnWatcher {
             guard let document = PDFDocument(url: url),
                   AnnotationInspector.isShotdeckDocument(document) else { continue }
             guard let inspected = try? AnnotationInspector.inspect(fileURL: url) else { continue }
+            if !recordUncommented, !inspected.isCommented { continue }
             try await ledger.record(inspected)
             results.append(inspected)
         }

Sources/ShotdeckCore/Support/TransportSettings.swift

@@ -0,0 +1,145 @@
+import Foundation
+
+/// The two ways a composed PDF can reach the iPad and come back marked up.
+public enum SendTransport: String, Codable, Sendable, CaseIterable {
+    case airDrop
+    case oneDrive
+
+    public var displayName: String {
+        switch self {
+        case .airDrop: return "AirDrop"
+        case .oneDrive: return "OneDrive folder"
+        }
+    }
+}
+
+/// User-configurable transport choice plus the OneDrive folder override, backed by
+/// UserDefaults the same way `FolderSettings` is. See `FolderSettings` for why a plain
+/// path (not a security-scoped bookmark) is correct for this unsandboxed app.
+public enum TransportSettings {
+    public static let transportDefaultsKey = "ai.flowmaster.shotdeck.transport"
+    public static let oneDriveFolderDefaultsKey = "ai.flowmaster.shotdeck.oneDriveFolder"
+
+    /// Defaults to `.airDrop` when unset or when the stored value cannot be parsed.
+    public static func transport(defaults: UserDefaults = .standard) -> SendTransport {
+        guard let raw = defaults.string(forKey: transportDefaultsKey),
+              let value = SendTransport(rawValue: raw)
+        else { return .airDrop }
+        return value
+    }
+
+    public static func setTransport(_ value: SendTransport, defaults: UserDefaults = .standard) {
+        defaults.set(value.rawValue, forKey: transportDefaultsKey)
+    }
+
+    /// Raw stored path (or nil if never set / cleared). Does NOT validate that the
+    /// directory still exists.
+    public static func storedOneDriveFolderPath(defaults: UserDefaults = .standard) -> String? {
+        defaults.string(forKey: oneDriveFolderDefaultsKey)
+    }
+
+    public static func setOneDriveFolder(_ url: URL, defaults: UserDefaults = .standard) {
+        defaults.set(url.path, forKey: oneDriveFolderDefaultsKey)
+    }
+
+    public static func resetOneDriveFolder(defaults: UserDefaults = .standard) {
+        defaults.removeObject(forKey: oneDriveFolderDefaultsKey)
+    }
+
+    /// The outbox/watch folders Redline should actually use right now, for the current
+    /// transport. AirDrop mode delegates to `FolderSettings.resolve()` unchanged.
+    /// OneDrive mode uses the SAME folder for both outbox and watch — see
+    /// `OneDriveLocator.resolveOneDriveFolder`. When no OneDrive folder can be resolved
+    /// at all (no sync root, no override), this falls back to the AirDrop folders so the
+    /// app always has somewhere to write; `send(anchor:)` performs its own live
+    /// existence check before ever composing into a OneDrive send, so that fallback is
+    /// never mistaken for a valid OneDrive destination.
+    public static func effectiveFolders(
+        defaults: UserDefaults = .standard,
+        fileManager: FileManager = .default
+    ) -> (outbox: URL, watch: URL, transport: SendTransport) {
+        let transport = transport(defaults: defaults)
+        switch transport {
+        case .airDrop:
+            let folders = FolderSettings.resolve(defaults: defaults, fileManager: fileManager)
+            return (folders.outbox, folders.watch, transport)
+        case .oneDrive:
+            if let folder = OneDriveLocator.resolveOneDriveFolder(
+                defaults: defaults,
+                home: fileManager.homeDirectoryForCurrentUser,
+                fileManager: fileManager
+            ) {
+                return (folder, folder, transport)
+            }
+            let folders = FolderSettings.resolve(defaults: defaults, fileManager: fileManager)
+            return (folders.outbox, folders.watch, transport)
+        }
+    }
+}
+
+/// Pure path logic for locating a OneDrive sync root under
+/// `~/Library/CloudStorage` and the Redline folder inside it. No side effects — never
+/// creates a directory. Fully unit-testable with a fake home tree.
+public enum OneDriveLocator {
+    /// Every directory directly under `<home>/Library/CloudStorage` whose name starts
+    /// with "OneDrive-", sorted so a name containing "MMD" (case-insensitive) sorts
+    /// first, then alphabetically. Empty when CloudStorage does not exist.
+    public static func syncRoots(
+        home: URL = FileManager.default.homeDirectoryForCurrentUser,
+        fileManager: FileManager = .default
+    ) -> [URL] {
+        let cloudStorage = home.appendingPathComponent("Library/CloudStorage", isDirectory: true)
+        var isDirectory: ObjCBool = false
+        guard fileManager.fileExists(atPath: cloudStorage.path, isDirectory: &isDirectory),
+              isDirectory.boolValue
+        else { return [] }
+
+        let items = (try? fileManager.contentsOfDirectory(
+            at: cloudStorage,
+            includingPropertiesForKeys: [.isDirectoryKey],
+            options: [.skipsHiddenFiles]
+        )) ?? []
+
+        let roots = items.filter { url in
+            guard url.lastPathComponent.hasPrefix("OneDrive-") else { return false }
+            var itemIsDirectory: ObjCBool = false
+            let exists = fileManager.fileExists(atPath: url.path, isDirectory: &itemIsDirectory)
+            return exists && itemIsDirectory.boolValue
+        }
+
+        return roots.sorted { a, b in
+            let aName = a.lastPathComponent
+            let bName = b.lastPathComponent
+            let aIsMMD = aName.localizedCaseInsensitiveContains("MMD")
+            let bIsMMD = bName.localizedCaseInsensitiveContains("MMD")
+            if aIsMMD != bIsMMD { return aIsMMD }
+            return aName.localizedStandardCompare(bName) == .orderedAscending
+        }
+    }
+
+    /// First sync root's "Redline" subfolder, or nil when there is no sync root at all.
+    public static func defaultRedlineFolder(
+        home: URL = FileManager.default.homeDirectoryForCurrentUser,
+        fileManager: FileManager = .default
+    ) -> URL? {
+        guard let first = syncRoots(home: home, fileManager: fileManager).first else { return nil }
+        return first.appendingPathComponent("Redline", isDirectory: true)
+    }
+
+    /// The stored override when it is set AND still exists as a directory; otherwise
+    /// `defaultRedlineFolder`. Never creates anything.
+    public static func resolveOneDriveFolder(
+        defaults: UserDefaults = .standard,
+        home: URL = FileManager.default.homeDirectoryForCurrentUser,
+        fileManager: FileManager = .default
+    ) -> URL? {
+        if let storedPath = TransportSettings.storedOneDriveFolderPath(defaults: defaults) {
+            var isDirectory: ObjCBool = false
+            let exists = fileManager.fileExists(atPath: storedPath, isDirectory: &isDirectory)
+            if exists, isDirectory.boolValue {
+                return URL(fileURLWithPath: storedPath, isDirectory: true)
+            }
+        }
+        return defaultRedlineFolder(home: home, fileManager: fileManager)
+    }
+}

Tests/ShotdeckCoreTests/OneDriveLocatorTests.swift

@@ -0,0 +1,125 @@
+import Foundation
+import Testing
+import ShotdeckCore
+
+@Test
+func syncRootsFindsOneDriveDirsMMDFirstIgnoresNonDirsAndOtherProviders() throws {
+    let home = try makeFakeHome()
+    defer { try? FileManager.default.removeItem(at: home) }
+    let cloudStorage = home.appendingPathComponent("Library/CloudStorage", isDirectory: true)
+    try FileManager.default.createDirectory(at: cloudStorage, withIntermediateDirectories: true)
+
+    try FileManager.default.createDirectory(
+        at: cloudStorage.appendingPathComponent("OneDrive-Flowmaster", isDirectory: true),
+        withIntermediateDirectories: true
+    )
+    try FileManager.default.createDirectory(
+        at: cloudStorage.appendingPathComponent("OneDrive-MMDGROUP", isDirectory: true),
+        withIntermediateDirectories: true
+    )
+    try FileManager.default.createDirectory(
+        at: cloudStorage.appendingPathComponent("GoogleDrive-x", isDirectory: true),
+        withIntermediateDirectories: true
+    )
+    // A plain FILE (not a directory) named like a OneDrive root must be ignored.
+    FileManager.default.createFile(
+        atPath: cloudStorage.appendingPathComponent("OneDrive-notadir").path,
+        contents: Data("not a directory".utf8)
+    )
+
+    let roots = OneDriveLocator.syncRoots(home: home, fileManager: .default)
+
+    #expect(roots.map(\.lastPathComponent) == ["OneDrive-MMDGROUP", "OneDrive-Flowmaster"])
+}
+
+@Test
+func syncRootsEmptyAndDefaultFolderNilWithNoCloudStorageDirectory() throws {
+    let home = try makeFakeHome()
+    defer { try? FileManager.default.removeItem(at: home) }
+    // No Library/CloudStorage created at all.
+
+    let roots = OneDriveLocator.syncRoots(home: home, fileManager: .default)
+    #expect(roots.isEmpty)
+
+    let defaultFolder = OneDriveLocator.defaultRedlineFolder(home: home, fileManager: .default)
+    #expect(defaultFolder == nil)
+}
+
+@Test
+func defaultRedlineFolderIsFirstSyncRootPlusRedline() throws {
+    let home = try makeFakeHome()
+    defer { try? FileManager.default.removeItem(at: home) }
+    let cloudStorage = home.appendingPathComponent("Library/CloudStorage", isDirectory: true)
+    try FileManager.default.createDirectory(
+        at: cloudStorage.appendingPathComponent("OneDrive-MMDGROUP", isDirectory: true),
+        withIntermediateDirectories: true
+    )
+    try FileManager.default.createDirectory(
+        at: cloudStorage.appendingPathComponent("OneDrive-Flowmaster", isDirectory: true),
+        withIntermediateDirectories: true
+    )
+
+    let defaultFolder = try #require(
+        OneDriveLocator.defaultRedlineFolder(home: home, fileManager: .default)
+    )
+    // Derive "expected" from syncRoots() itself (already covered by its own dedicated
+    // test) rather than hand-building the path string — FileManager's directory
+    // enumeration can canonicalize /var -> /private/var and the two constructions
+    // otherwise disagree on that even for a URL that already exists.
+    let expectedRoot = try #require(OneDriveLocator.syncRoots(home: home, fileManager: .default).first)
+    let expected = expectedRoot.appendingPathComponent("Redline", isDirectory: true)
+    #expect(defaultFolder.path == expected.path)
+}
+
+@Test
+func resolveOneDriveFolderPrefersAnExistingStoredOverride() throws {
+    let home = try makeFakeHome()
+    defer { try? FileManager.default.removeItem(at: home) }
+    let cloudStorage = home.appendingPathComponent("Library/CloudStorage", isDirectory: true)
+    try FileManager.default.createDirectory(
+        at: cloudStorage.appendingPathComponent("OneDrive-MMDGROUP", isDirectory: true),
+        withIntermediateDirectories: true
+    )
+
+    let suite = try makeTransportDefaultsSuite()
+    defer { tearDownTransportSuite(suite) }
+    let override = try makeTransportTemporaryDirectory(prefix: "shotdeck-onedrive-override")
+    defer { try? FileManager.default.removeItem(at: override) }
+    TransportSettings.setOneDriveFolder(override, defaults: suite.defaults)
+
+    let resolved = OneDriveLocator.resolveOneDriveFolder(
+        defaults: suite.defaults, home: home, fileManager: .default
+    )
+    #expect(resolved?.path == override.path)
+}
+
+@Test
+func resolveOneDriveFolderIgnoresAStoredPathThatNoLongerExists() throws {
+    let home = try makeFakeHome()
+    defer { try? FileManager.default.removeItem(at: home) }
+    let cloudStorage = home.appendingPathComponent("Library/CloudStorage", isDirectory: true)
+    try FileManager.default.createDirectory(
+        at: cloudStorage.appendingPathComponent("OneDrive-MMDGROUP", isDirectory: true),
+        withIntermediateDirectories: true
+    )
+
+    let suite = try makeTransportDefaultsSuite()
+    defer { tearDownTransportSuite(suite) }
+    let goneOverride = try makeTransportTemporaryDirectory(prefix: "shotdeck-onedrive-gone")
+    TransportSettings.setOneDriveFolder(goneOverride, defaults: suite.defaults)
+    try FileManager.default.removeItem(at: goneOverride)
+
+    let resolved = OneDriveLocator.resolveOneDriveFolder(
+        defaults: suite.defaults, home: home, fileManager: .default
+    )
+    let expectedRoot = try #require(OneDriveLocator.syncRoots(home: home, fileManager: .default).first)
+    let expected = expectedRoot.appendingPathComponent("Redline", isDirectory: true)
+    #expect(resolved?.path == expected.path)
+}
+
+private func makeFakeHome() throws -> URL {
+    let home = FileManager.default.temporaryDirectory
+        .appendingPathComponent("shotdeck-fake-home-\(UUID().uuidString)", isDirectory: true)
+    try FileManager.default.createDirectory(at: home, withIntermediateDirectories: true)
+    return home
+}

Tests/ShotdeckCoreTests/ReturnWatcherTests.swift

@@ -230,3 +230,55 @@ func w27_fsEventsCallbackFiresOnRealArrival() async throws {
         await watcher.stop()
     }
 }
+
+@Test("recordUncommented defaults to true: an unmarked PDF is still recorded (AirDrop behaviour unchanged)")
+func recordUncommentedDefaultTrueRecordsAnUnmarkedPDF() async throws {
+    let (paths, cleanup) = try makeCasePaths()
+    defer { try? FileManager.default.removeItem(at: cleanup) }
+
+    let ledger = try ReturnLedger(paths: paths)
+    let watcher = ReturnWatcher(paths: paths, ledger: ledger)
+    let pdfURL = paths.watchFolder.appendingPathComponent("Redline-20260905-090000.pdf")
+
+    try makePDF(at: pdfURL, pageCount: 1, creator: "Redline", annotations: [])
+
+    let found = try await watcher.scanNow()
+    #expect(found.count == 1)
+    #expect(found.first?.isCommented == false)
+
+    let all = try await ledger.all()
+    #expect(all.count == 1)
+}
+
+@Test("recordUncommented=false: an unmarked PDF is not recorded or returned; marking it up in place gets it recorded")
+func recordUncommentedFalseSkipsUnmarkedThenRecordsAfterInPlaceMarkup() async throws {
+    let (paths, cleanup) = try makeCasePaths()
+    defer { try? FileManager.default.removeItem(at: cleanup) }
+
+    let ledger = try ReturnLedger(paths: paths)
+    let watcher = ReturnWatcher(paths: paths, ledger: ledger)
+    await watcher.setRecordUncommented(false)
+    let pdfURL = paths.watchFolder.appendingPathComponent("Redline-20260905-091500.pdf")
+
+    // OneDrive mode: the PDF is freshly written here (by "send"), unmarked so far.
+    try makePDF(at: pdfURL, pageCount: 1, creator: "Redline", annotations: [])
+
+    let beforeMarkup = try await watcher.scanNow()
+    #expect(beforeMarkup.isEmpty)
+    let allBefore = try await ledger.all()
+    #expect(allBefore.isEmpty)
+
+    // What the iPad does: mark it up in place, in the SAME folder, then save.
+    let document = try #require(PDFDocument(url: pdfURL))
+    let page = try #require(document.page(at: 0))
+    page.addAnnotation(makeAnnotation(.ink, bounds: CGRect(x: 100, y: 100, width: 120, height: 50)))
+    #expect(document.write(to: pdfURL))
+
+    let afterMarkup = try await watcher.scanNow()
+    #expect(afterMarkup.count == 1)
+    #expect(afterMarkup.first?.isCommented == true)
+
+    let commented = try await ledger.commented()
+    #expect(commented.count == 1)
+    #expect(commented.first?.fileURL.resolvingSymlinksInPath().path == pdfURL.resolvingSymlinksInPath().path)
+}

Tests/ShotdeckCoreTests/TransportSettingsTests.swift

@@ -0,0 +1,114 @@
+import Foundation
+import Testing
+import ShotdeckCore
+
+@Test
+func transportDefaultsToAirDropWhenUnset() throws {
+    let suite = try makeTransportDefaultsSuite()
+    defer { tearDownTransportSuite(suite) }
+
+    #expect(TransportSettings.transport(defaults: suite.defaults) == .airDrop)
+}
+
+@Test
+func setTransportRoundTrips() throws {
+    let suite = try makeTransportDefaultsSuite()
+    defer { tearDownTransportSuite(suite) }
+
+    TransportSettings.setTransport(.oneDrive, defaults: suite.defaults)
+    #expect(TransportSettings.transport(defaults: suite.defaults) == .oneDrive)
+
+    TransportSettings.setTransport(.airDrop, defaults: suite.defaults)
+    #expect(TransportSettings.transport(defaults: suite.defaults) == .airDrop)
+}
+
+@Test
+func garbageStoredTransportFallsBackToAirDrop() throws {
+    let suite = try makeTransportDefaultsSuite()
+    defer { tearDownTransportSuite(suite) }
+
+    suite.defaults.set("not-a-real-transport", forKey: TransportSettings.transportDefaultsKey)
+    #expect(TransportSettings.transport(defaults: suite.defaults) == .airDrop)
+}
+
+@Test
+func oneDriveFolderStoreAndReset() throws {
+    let suite = try makeTransportDefaultsSuite()
+    defer { tearDownTransportSuite(suite) }
+    let folder = try makeTransportTemporaryDirectory(prefix: "shotdeck-onedrive-folder")
+    defer { try? FileManager.default.removeItem(at: folder) }
+
+    #expect(TransportSettings.storedOneDriveFolderPath(defaults: suite.defaults) == nil)
+
+    TransportSettings.setOneDriveFolder(folder, defaults: suite.defaults)
+    #expect(TransportSettings.storedOneDriveFolderPath(defaults: suite.defaults) == folder.path)
+
+    TransportSettings.resetOneDriveFolder(defaults: suite.defaults)
+    #expect(TransportSettings.storedOneDriveFolderPath(defaults: suite.defaults) == nil)
+}
+
+@Test
+func effectiveFoldersForAirDropMatchesFolderSettings() throws {
+    let suite = try makeTransportDefaultsSuite()
+    defer { tearDownTransportSuite(suite) }
+    let outbox = try makeTransportTemporaryDirectory(prefix: "shotdeck-effective-outbox")
+    defer { try? FileManager.default.removeItem(at: outbox) }
+    FolderSettings.setOutbox(outbox, defaults: suite.defaults)
+
+    let effective = TransportSettings.effectiveFolders(defaults: suite.defaults)
+    let expected = FolderSettings.resolve(defaults: suite.defaults)
+
+    #expect(effective.transport == .airDrop)
+    #expect(effective.outbox.path == expected.outbox.path)
+    #expect(effective.watch.path == expected.watch.path)
+}
+
+@Test
+func effectiveFoldersForOneDriveWithAResolvableFolderUsesItForBoth() throws {
+    let suite = try makeTransportDefaultsSuite()
+    defer { tearDownTransportSuite(suite) }
+    let folder = try makeTransportTemporaryDirectory(prefix: "shotdeck-effective-onedrive")
+    defer { try? FileManager.default.removeItem(at: folder) }
+
+    TransportSettings.setTransport(.oneDrive, defaults: suite.defaults)
+    TransportSettings.setOneDriveFolder(folder, defaults: suite.defaults)
+
+    let effective = TransportSettings.effectiveFolders(defaults: suite.defaults)
+
+    #expect(effective.transport == .oneDrive)
+    #expect(effective.outbox.path == folder.path)
+    #expect(effective.watch.path == folder.path)
+    #expect(effective.outbox.path == effective.watch.path)
+}
+
+@Test
+func oneDriveFolderUnavailableErrorDescriptionContainsThePath() throws {
+    let path = "/Users/example/Library/CloudStorage/OneDrive-Example/Redline"
+    let error = ShotdeckError.oneDriveFolderUnavailable(path: path)
+    let description = try #require(error.errorDescription)
+    #expect(!description.isEmpty)
+    #expect(description.contains(path))
+}
+
+struct TransportDefaultsSuite {
+    let name: String
+    let defaults: UserDefaults
+}
+
+func makeTransportDefaultsSuite() throws -> TransportDefaultsSuite {
+    let name = "shotdeck-transport-test-\(UUID().uuidString)"
+    let defaults = try #require(UserDefaults(suiteName: name))
+    defaults.removePersistentDomain(forName: name)
+    return TransportDefaultsSuite(name: name, defaults: defaults)
+}
+
+func tearDownTransportSuite(_ suite: TransportDefaultsSuite) {
+    suite.defaults.removePersistentDomain(forName: suite.name)
+}
+
+func makeTransportTemporaryDirectory(prefix: String) throws -> URL {
+    let url = FileManager.default.temporaryDirectory
+        .appendingPathComponent("\(prefix)-\(UUID().uuidString)", isDirectory: true)
+    try FileManager.default.createDirectory(at: url, withIntermediateDirectories: true)
+    return url
+}