feat: add per-trip use_gpx and autoconnect toggles

Adds two configurable toggles to the trip blueprint (Admin2 Trip tab):
- use_gpx: show/hide GPX tracks on all maps (default: enabled)
- autoconnect: draw connector lines between markers (default: enabled)

When use_gpx is off, GPX files are not fetched or rendered on any map
(home, map, trip, dailies). The stats panel in trip.html.twig still
reads GPX_URLS directly and is unaffected.

When autoconnect is off, buildJourneySegments suppresses all
auto-connectors; only entries with force_connect:true still draw a
line — making force_connect behaviour independent of both settings.

Also refactors the inline Promise.all in trip.html.twig to use the
shared renderGpxJourney utility (reducing duplication).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Vgmzx8VTTTmCskSpQtsLTr

themes/intotheeast/templates/home.html.twig

@@ -151,6 +151,8 @@
 <script>
 var HOME_ENTRIES  = {{ map_entries|json_encode|raw }};
 var HOME_GPX_URLS = {{ home_gpx_urls|json_encode|raw }};
+var USE_GPX       = {{ trip and trip.header.use_gpx is not null ? (trip.header.use_gpx ? 'true' : 'false') : 'true' }};
+var AUTOCONNECT   = {{ trip and trip.header.autoconnect is not null ? (trip.header.autoconnect ? 'true' : 'false') : 'true' }};
 
 var homeMap = new maplibregl.Map({
     container: 'home-map',
@@ -192,7 +194,7 @@ homeMap.on('load', function () {
 
     setTimeout(function () { homeMap.resize(); }, 100);
 
-    MapUtils.renderGpxJourney(homeMap, HOME_GPX_URLS, HOME_ENTRIES, 'home-gpx', 'home-journey');
+    MapUtils.renderGpxJourney(homeMap, USE_GPX ? HOME_GPX_URLS : [], HOME_ENTRIES, 'home-gpx', 'home-journey', { autoconnect: AUTOCONNECT });
 });
 </script>
 {% endif %}