[marinofaggiana]

Replace the legacy passcode implementation in the main app and Share Extension with shared SwiftUI components for app unlocking, passcode creation, change and removal, and E2EE authentication. Remove TOPasscodeViewController and its obsolete wrappers, and update third-party acknowledgements.

The implementation keeps the existing Keychain credentials and preferences, supports Face ID and Touch ID, and shares failed-attempt counters and lockout deadlines across passcode operations. Optional requests cancel when their scene enters the background; mandatory app unlocking remains non-dismissible. A dedicated window per scene presents the mandatory lock independently of existing sheets and alerts.

Fix the cumulative failed-attempt counter being cleared when the temporary lockout expires: the 60-second delay after three incorrect attempts now preserves the total used by the optional reset-after-ten-attempts policy. Successful authentication still clears both counters.

Local UI tests

The seven XCUITests in PasscodeUITests are intended to run locally. The CI test command explicitly excludes this suite with -skip-testing:NextcloudUITests/PasscodeUITests; it still compiles the tests and runs the remaining enabled tests. A green CI run therefore does not validate these seven scenarios.

Setup and execution

1. Use Xcode 27.1 or newer and a dedicated iOS simulator. Set the simulator's system language to English; the shared Test action also uses English / United States. Use a disposable test environment: the last test deliberately resets the app and removes its local data and credentials.
2. Start Docker Desktop and prepare a Nextcloud stable30 server at http://localhost:8080, with credentials admin / admin. The repository provides Tests/Server.sh. Keep the server running throughout the tests.
3. Ensure the server's web login uses English:

   docker exec --user www-data xcode-test-server php /var/www/html/occ config:system:set force_language --value=en
   curl --fail --show-error http://localhost:8080/status.php

   The status response should show installed: true, maintenance: false and needsDbUpgrade: false.
4. Open Nextcloud.xcodeproj, select the Nextcloud scheme and the dedicated simulator, then open the Test navigator (⌘6). Run NextcloudUITests → PasscodeUITests, or run individual methods while investigating a failure.
5. Allow the full suite to finish. The reset test crosses three real 60-second lockouts, so it takes at least three minutes on its own. Inspect the test report and retained diagnostic attachments if a test fails.

The Debug-only setup guarded by UI_TESTING and UI_TESTING_PASSCODE resets the passcode, counters and related lock settings before each test. The login helper reuses an existing signed-in account or performs the real web login when needed, including dismissal of the password-saving prompt. Persistence checks relaunch without the setup flags so stored credentials, counters and deadlines are preserved.

Scenarios covered

Test	Expected behavior
testCreateChangeAndDisablePasscode	Create and change the code; reject the old code; disable the lock with the new code.
testDisableLockoutSurvivesReopeningBackgroundAndRelaunch	Preserve failed attempts and the original lockout deadline across reopening, background/foreground transitions and process relaunch.
testChangePasscodeCannotResetFailedAttemptsByReopening	Reopening the change-code sheet cannot clear failed attempts or bypass the lockout.
testBackgroundCannotBypassMandatoryAppLock	Returning from background presents a non-dismissible lock; settings underneath remain inaccessible and dragging cannot dismiss it.
testAppLockAppearsAbovePresentedSheet	The lock covers an existing Acknowledgements sheet, which remains open after successful authentication.
testAppLockAppearsAbovePresentedAlert	The lock covers an existing Clear cache confirmation alert, which remains open after successful authentication.
testAppResetAfterTenFailuresAcrossLockouts	With reset enabled, ten wrong codes across three lockouts reset and close the app; relaunch shows login without the old passcode.

Additional manual verification

• Face ID / Touch ID success, failure and cancellation on a supported device.
• Share Extension and E2EE authentication, including cancellation and reset behavior.
• Independent locking of multiple scenes on iPad.

🤖 AI (if applicable)

• The content of this PR was partly or fully generated using AI