feat: expand connect markers to 4-mode select

Replaces the boolean toggle with a select field offering:
  on             — connect all consecutive entries (chronological line)
  manual         — force_connect entries only (user-controlled connections)
  intelligent_gpx — suppress connectors where GPX covers both endpoints;
                    force_connect overrides (original smart logic, restored)
  off            — no connectors at all; force_connect also ignored

buildJourneySegments gains an optional trackpointsPerFile param used
only by intelligent_gpx mode. renderGpxJourney extracts trackpoints
only when connectMode is intelligent_gpx. dailies.html.twig falls
back from intelligent_gpx → on (mini-map has no GPX tracks to
suppress against).

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

themes/intotheeast/blueprints/trip.yaml

@@ -68,16 +68,15 @@ form:
                 type: bool
 
             header.autoconnect:
-              type: toggle
+              type: select
               label: Connect markers
-              help: 'Draw connector lines between all location markers in chronological order'
-              highlight: 1
-              default: 1
+              help: 'Controls connector lines between location markers'
+              default: 'on'
               options:
-                1: 'Yes'
-                0: 'No'
-              validate:
-                type: bool
+                'on': 'On — always connect all'
+                'manual': 'Manual — force connect only'
+                'intelligent_gpx': 'Intelligent GPX — suppress where route is covered'
+                'off': 'Off — no connections'
 
         publishing:
           type: tab