v1.5.35 — Modal fix, wizard step visibility & styling

Fixed

• All modals unblocked — the `.bcg-modal-overlay[id]` CSS rule was accidentally promoting inner backdrop divs (Preview, Load Template, AI Prompt, What's New, Request a Section) to `position: fixed`, placing them on top of the modal content and blocking all clicks. The rule now targets only `#bcg-schedule-modal` which legitimately uses the overlay-as-root pattern.
• What's New overlay — removed the `id` attribute from the inner backdrop div (replaced with class `bcg-whats-new-overlay`) and updated the JS dismiss handler to use the class selector.
• Wizard steps hidden behind sticky header — on page load the JS was scrolling the wizard steps to the top of the viewport, landing them under the sticky plugin header (32px admin bar + 52px header). Scroll offset increased from 40px to 100px; added `scroll-margin-top: 100px` to the container.
• Wizard step title colour — fallback colour changed from dark `#2d3748` to light `#f0f4f8` so titles are readable on dark page backgrounds.
• Wizard connector line — removed the `margin-top: -20px` hack; the steps container now uses `align-items: center` so the connector line is vertically centred with the step circles.