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/SettingsView.swift

@@ -77,7 +77,7 @@ struct SettingsView: View {
             } else {
                 GridRow(alignment: .center) {
                     fieldLabel("OneDrive folder")
-                    if let folder = resolvedOneDriveFolder {
+                    if let folder = model.resolvedOneDriveFolder {
                         folderValue(path: folder.path) {
                             model.chooseOneDriveFolder()
                         }
@@ -122,13 +122,6 @@ struct SettingsView: View {
         Binding(get: { model.transport }, set: { model.chooseTransport($0) })
     }
 
-    /// Ground truth from OneDriveLocator, not `model.outboxURL` — the model may be
-    /// showing an AirDrop-folder fallback when no real OneDrive folder resolves, and
-    /// the Settings row must say so plainly rather than repeat that fallback path.
-    private var resolvedOneDriveFolder: URL? {
-        OneDriveLocator.resolveOneDriveFolder()
-    }
-
     private func armHotkeyRecorder() {
         guard !isRecordingHotkey else { return }
         isRecordingHotkey = true
@@ -267,6 +260,7 @@ extension AppModel: SettingsWindowPresenting {
             )
         }
         setFolderURLs(outbox: folders.outbox, watch: folders.watch)
+        setResolvedOneDriveFolder(OneDriveLocator.resolveOneDriveFolder())
         Task {
             await watcher.setRecordUncommented(value == .airDrop)
             do {
@@ -280,10 +274,11 @@ extension AppModel: SettingsWindowPresenting {
     }
 
     func chooseOneDriveFolder() {
-        let start = OneDriveLocator.resolveOneDriveFolder() ?? FileManager.default.homeDirectoryForCurrentUser
+        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 {