refactor(theme): extract home-predeparture partial; trip-feed-col single-purpose

Addresses code-review finding: the pre_departure branch made trip-feed-col
dual-purpose. Pre-departure landing now lives in its own partial; home picks
it via {% if all_items|length == 0 %}, and trip-feed-col drops the
pre_departure param to be shared 1:1 by both callers.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BftDn9vu9SonFAY4vxu4uk

themes/intotheeast/templates/home.html.twig

@@ -64,18 +64,23 @@
         <div class="home-map" id="home-map"></div>
     </div>
 
-    {% include 'partials/trip-feed-col.html.twig' with {
-        trip_page: trip,
-        all_items: all_items,
-        journal_entries: journal_entries,
-        journal_count: journal_count,
-        story_count: story_count,
-        has_gpx: home_gpx_urls|length > 0,
-        gpx_urls: home_gpx_urls,
-        gps_points: gps_points,
-        show_sort: false,
-        pre_departure: all_items|length == 0
-    } only %}
+    {% if all_items|length == 0 %}
+        {% include 'partials/home-predeparture.html.twig' with {
+            trip_page: trip
+        } only %}
+    {% else %}
+        {% include 'partials/trip-feed-col.html.twig' with {
+            trip_page: trip,
+            all_items: all_items,
+            journal_entries: journal_entries,
+            journal_count: journal_count,
+            story_count: story_count,
+            has_gpx: home_gpx_urls|length > 0,
+            gpx_urls: home_gpx_urls,
+            gps_points: gps_points,
+            show_sort: false
+        } only %}
+    {% endif %}
 </div>
 
 {% if map_entries|length > 0 %}