Feature and design improvements

Improvements to pages without named selectors and other optimizations.

What's new in 0.7.0:

• Screenshots — add a "Screenshot" step anywhere in a macro (draw a rectangle to
capture just part of the page, or grab the whole tab). Every bulk run also
auto-captures a screenshot after each row completes. All screenshots save
straight to your Downloads folder.
• Schedule — run a saved macro on a repeating timer (15 minutes to 24 hours),
even with the popup closed.
• Follows new tabs — a click that opens a new tab is now recorded and replayed
automatically, including closing it again afterward.
• Extract — capture a value the page shows you (a confirmation number, a
computed total) instead of clicking or typing into it, exported as its own
spreadsheet.
• "Don't navigate automatically" option, for replaying against whatever page
is already open.
• Multi-select dropdowns now record every option you choose, not just the
last one.
• New Advanced tab: hand-edit a macro as raw JSON, and choose where
auto-saved screenshots go.
• A full visual redesign — new color theme, clearer step numbering, better
light/dark mode support throughout.
• Several bug fixes: a clipped dropdown menu, stale spreadsheet data
surviving "Clear All", and faster, smarter replay timing.

updated theme and optimisation of functionality