feat: render the floor plan in html instead of svg

templates/booking/_modal_edit.html.twig

@@ -3,7 +3,7 @@
     this day moves, the rest of the series is untouched and the occurrence is flagged as
     differing from it.
 
-    Releasing lives here too rather than on the floor plan, so the SVG needs no confirm dialogs
+    Releasing lives here too rather than on the floor plan, so a card needs no confirm dialogs
     or inline CSRF tokens -- clicking your own desk always just opens this. The release button
     opens the shared confirmation modal over this one.
 #}