Refactor server startup: elimina segfaults, añade leaflet-workaround

Retira import './segfaults' (workaround de crash obsoleto) y añade
leaflet-workaround.js (shims global window/document/navigator para
render de Leaflet en servidor). Ajustes menores en publications de
FalsePositives y subsUnion.

imports/startup/server/index.js

@@ -17,5 +17,4 @@ import './prerender';
 import './feedback';
 import './cron';
 import './isMaster';
-import './segfaults';
 import './rest';