Sync docs with recent plugin changes; formatting and placeholder cleanup

- Document the new Panel Text Color control on Woo Custom Product Tabs
  (dotjuice-elementor-tools-pro 20260817.1)
- Document Dark Mode Toggle now persisting site-wide (pages without the
  toggle) and applying before first paint (dotjuice-elementor-tools
  c33084e)
- Add blank line before headings following image captions across pro
  widget docs, so they render correctly
- Regenerate placeholder screenshots for pro widget and pagespeed docs
- Remove stray H1 from the free plugin marketing overview (post title
  already serves as H1, matching the other marketing files)
- Bump local dev port to 3080, drop unused site/docs/.gitkeep

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SZsdkGdZYtCS6hZaX92NQ6

docs/dotjuice-elementor-tools/widgets/dark-mode-toggle.md

@@ -9,7 +9,7 @@ Found in the Elementor panel under **Dotjuice → Dark Mode Toggle**.
 
 ## How it works
 
-The widget renders a small clickable icon. Clicking it adds a dark-mode class to your entire site and swaps your global colours for the dark-mode values you configure on the widget. The choice is stored in the visitor's browser, so it survives navigation and returns on their next visit.
+The widget renders a small clickable icon. Clicking it adds a dark-mode class to your entire site and swaps your global colours for the dark-mode values you configure on the widget. The choice is stored in the visitor's browser, so it survives navigation and returns on their next visit — including on pages and templates that don't have the toggle on them at all, as long as the toggle exists somewhere on the site. Dark mode is applied before the page paints, so there's no flash of light-mode colours first.
 
 It works with **both** of Elementor's global-colour systems: