feat: add FileBookmarkService, BiometricAuthService, ClipboardService

Phase 3 (Tasks 10-11) app services: FileBookmarkService persists a
security-scoped bookmark for the KDBX file in the shared App Group;
BiometricAuthService wraps LAContext for Face ID/Touch ID; ClipboardService
copies text with an expiring clipboard entry on iOS/macOS.

Also fixes a real build issue found while verifying: the AutoFill
extension (iOS-only) was being embedded/signed unconditionally,
breaking macOS builds of the MyPass scheme with a bogus provisioning
error. Added platformFilters = (ios) to both the embed build file and
the target dependency so macOS builds skip it. Verified both iOS
Simulator and macOS builds now fail only on the known, expected
ContentView.swift/Item SwiftData breakage.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WYqycDFsynHH9VnnK7LNSf

MyPass/Services/BiometricAuthService.swift

@@ -0,0 +1,23 @@
+//
+//  BiometricAuthService.swift
+//  MyPass
+//
+
+import LocalAuthentication
+import Foundation
+
+public final class BiometricAuthService {
+    public init() {}
+
+    public var isAvailable: Bool {
+        let ctx = LAContext()
+        var error: NSError?
+        return ctx.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: &error)
+    }
+
+    /// Returns true on success. On failure, throws an error with a localized message.
+    public func authenticate(reason: String) async throws {
+        let ctx = LAContext()
+        try await ctx.evaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, localizedReason: reason)
+    }
+}

MyPass/Services/ClipboardService.swift

@@ -0,0 +1,30 @@
+//
+//  ClipboardService.swift
+//  MyPass
+//
+
+import Foundation
+#if os(iOS)
+import UIKit
+#else
+import AppKit
+#endif
+
+public enum ClipboardService {
+    public static func copy(_ text: String, expiresAfter seconds: TimeInterval = 30) {
+        #if os(iOS)
+        UIPasteboard.general.setItems(
+            [[UIPasteboard.typeAutomatic: text]],
+            options: [.expirationDate: Date().addingTimeInterval(seconds)]
+        )
+        #else
+        let pb = NSPasteboard.general
+        pb.clearContents()
+        pb.setString(text, forType: .string)
+        let captured = text
+        DispatchQueue.main.asyncAfter(deadline: .now() + seconds) {
+            if pb.string(forType: .string) == captured { pb.clearContents() }
+        }
+        #endif
+    }
+}

MyPass/Services/FileBookmarkService.swift

@@ -0,0 +1,60 @@
+//
+//  FileBookmarkService.swift
+//  MyPass
+//
+
+import Foundation
+
+/// Persists a security-scoped bookmark for the user's KDBX file in the shared App Group.
+public final class FileBookmarkService {
+    private static let key = "kdbxBookmark"
+    private let defaults: UserDefaults
+
+    public init(appGroup: String = "group.org.antiloop222.mypass") {
+        defaults = UserDefaults(suiteName: appGroup) ?? .standard
+    }
+
+    public func save(url: URL) throws {
+        let data = try url.bookmarkData(
+            options: .withSecurityScope,
+            includingResourceValuesForKeys: nil,
+            relativeTo: nil
+        )
+        defaults.set(data, forKey: Self.key)
+    }
+
+    /// Returns the resolved URL, starting security access. Caller must call `stopAccess(url:)` when done.
+    public func resolveURL() throws -> URL {
+        guard let data = defaults.data(forKey: Self.key) else { throw BookmarkError.notFound }
+        var isStale = false
+        let url = try URL(
+            resolvingBookmarkData: data,
+            options: .withSecurityScope,
+            relativeTo: nil,
+            bookmarkDataIsStale: &isStale
+        )
+        if isStale {
+            let fresh = try url.bookmarkData(options: .withSecurityScope, includingResourceValuesForKeys: nil, relativeTo: nil)
+            defaults.set(fresh, forKey: Self.key)
+        }
+        guard url.startAccessingSecurityScopedResource() else { throw BookmarkError.accessDenied }
+        return url
+    }
+
+    public func stopAccess(url: URL) {
+        url.stopAccessingSecurityScopedResource()
+    }
+
+    public func clear() {
+        defaults.removeObject(forKey: Self.key)
+    }
+
+    public var hasBookmark: Bool {
+        defaults.data(forKey: Self.key) != nil
+    }
+}
+
+public enum BookmarkError: Error {
+    case notFound
+    case accessDenied
+}