13-Dec-2025 — improve loading UX, control toggles, and boolean handling #102

Commit 9cd6d2d

adds a proper overlay/spinner cycle so heavy GPX maps don’t flash white while layers render
centralises boolean coercion in UiActionsService (with tests) and reuses it in index map + other consumers
keeps clustering + waypoint controls inline and respects visitor-lock states
brings ngx-bootstrap back to the safe version to clear the security warning
keep map preview and overlay sliders in sync so zoom/height/lat/lng edits persist and dragging the map feeds values back
refresh markers/center automatically when the location row changes and remember the “hide map options” preference for index rows
migrate linting to Angular ESLint with TypeScript configs/proxies to keep future changes gated