Main edit UX

- [x] Change cursor to make it clear what clicking will do
- [x] Adding a filter snaps to nearest road currently, but for one-ways, have to click a road exactly. Both are kind of clunky.
- [x] Deleting filter vs adding can conflict when cursor is over both
- [ ] Road labels seem to prevent the popup for filtering/oneways
- [ ] Try the thick outline style for hover instead of color+opacity
- [x] The edit panel/controls need re-thinking; they're probably worse than the old version
- [x] Basemap + colors / stuff drawn on top aren't as clear as old version
- [x] Warn loudly when a cell becomes disconnected

The issue describes multiple UX improvements for a web-based map editor. Start by exploring the frontend code for map interaction, cursor handling, and UI components. Look for existing road snapping, filter addition/deletion logic, and hover styling. Test the current behavior to understand the clunky interactions mentioned, then implement changes incrementally, ensuring road labels don't block popups and disconnected cells trigger warnings.

Written by the indexing model from the issue text.