chore: add DEBUG reveal of the CloudKit owner record IDchore/owner-record-id-reveal

Groundwork for the owner Pro+ allowlist. Adds OwnerAccess, which identifies the
app owner by their CloudKit user-record ID (a stable, opaque per-Apple-ID value
that cannot be guessed or spoofed), plus a DEBUG-only "Developer" row in
Settings → App Info that fetches and copies the current iCloud user's record ID
for the app's container.

OwnerAccess.ownerUserRecordID is empty, so isOwner() is inert until the real
value is filled in. A follow-up will hardcode the owner ID, wire isOwner() into
PurchaseService to grant .proPlus on a match, remove this reveal, and cut 5.0.1.

DEBUG-only UI; release builds are unaffected.

2 files changed, 58 insertions, 0 deletions

diff --git a/DomainDig/AppInfoView.swift b/DomainDig/AppInfoView.swift
index 055fe46..f3a0765 100644
--- a/DomainDig/AppInfoView.swift
+++ b/DomainDig/AppInfoView.swift
@@ -8,6 +8,9 @@ struct AppInfoView: View {
     @Environment(\.openURL) private var openURL
     @State private var cloudSyncService = CloudSyncService.shared
     @State private var activeSheet: AppInfoSheet?
+    #if DEBUG
+    @State private var developerRecordName: String?
+    #endif
 
     var body: some View {
         Form {
@@ -44,6 +47,27 @@ struct AppInfoView: View {
                 Text(AppLinks.copyright)
                     .frame(maxWidth: .infinity, alignment: .center)
             }
+
+            #if DEBUG
+            Section {
+                HStack(alignment: .top, spacing: 8) {
+                    Text(developerRecordName ?? "Fetching…")
+                        .font(.system(.footnote, design: .monospaced))
+                        .textSelection(.enabled)
+                    Spacer(minLength: 8)
+                    if let developerRecordName {
+                        AppCopyButton(value: developerRecordName, label: "Copy iCloud record ID")
+                    }
+                }
+            } header: {
+                Text("Developer")
+            } footer: {
+                Text("Your CloudKit user-record ID for this app, used to configure the owner allowlist. DEBUG builds only.")
+            }
+            .task {
+                developerRecordName = await OwnerAccess.currentUserRecordName() ?? "Unavailable (sign into iCloud)"
+            }
+            #endif
         }
         .navigationTitle("App Info")
         .task {
diff --git a/DomainDig/OwnerAccess.swift b/DomainDig/OwnerAccess.swift
new file mode 100644
index 0000000..be39a6c
--- /dev/null
+++ b/DomainDig/OwnerAccess.swift
@@ -0,0 +1,34 @@
+import CloudKit
+
+/// Owner-only entitlement support. The app owner is identified by their CloudKit
+/// user-record ID — a stable, opaque per-Apple-ID value for this app's container
+/// that other users cannot guess or spoof — so a release build can grant the
+/// owner Pro+ without a purchase.
+///
+/// `ownerUserRecordID` is empty until configured; an empty value never matches,
+/// so the allowlist is inert until the owner's real record ID is filled in. Read
+/// your own value from the DEBUG "Developer" row in Settings → App Info.
+enum OwnerAccess {
+    /// The owner's CloudKit user-record name. Empty = unconfigured (inert).
+    static let ownerUserRecordID = ""
+
+    static var isConfigured: Bool { !ownerUserRecordID.isEmpty }
+
+    /// The current iCloud user's record name for this app's container, or nil if
+    /// it is unavailable (not signed into iCloud, restricted, or offline before
+    /// the first fetch).
+    static func currentUserRecordName() async -> String? {
+        do {
+            return try await CKContainer.default().userRecordID().recordName
+        } catch {
+            return nil
+        }
+    }
+
+    /// True only when the allowlist is configured and the current iCloud user is
+    /// the owner.
+    static func isOwner() async -> Bool {
+        guard isConfigured else { return false }
+        return await currentUserRecordName() == ownerUserRecordID
+    }
+}