release/DEV-819: Prevent swiping through slides with error messages

[farhantariq12b]

DEV-819: The user can swipe through slides with error message on the screen

Parent ticket: DEV-473 - Single submission logic

Changes

• DEV-819 Disable swiper navigation (next, prev, touch) when a blocking error toast (duplicate submission or offline message) is shown, preventing users from swiping through slides while error messages are on screen
• DEV-819 Reload the page when user clicks OK on the submission-exists toast, unless a redirect action is configured
• DEV-819 Add hasBlockingError flag to persist swipe-disabled state through touchmove events so the swiper stays locked even after touch interactions

Files Changed

• js/libs/form.js — Added swiper disable logic in showSubmissionExistMessage() and showOfflineMessage(), added page reload on OK dismiss, and integrated hasBlockingError check into the touchmove swiper validation

Test Plan

• Multi-step form with single submission: submit once, trigger duplicate submission toast — verify slides cannot be swiped
• Click OK on the duplicate submission toast — verify page reloads
• Multi-step form with single submission + redirect configured — verify OK does NOT reload but follows redirect
• Offline scenario: trigger offline toast on multi-step form — verify slides cannot be swiped
• Normal multi-step form (no errors): verify swiping still works based on validation state
• Vertical scroll on slide component — verify it doesn't interfere with swipe lock

🤖 Generated with Claude Code

[galisufyan-327]

LGTM