fix: replace nonexistent Nunjucks min filter with inline conditional

The | min filter is Jinja2 syntax, not available in Nunjucks. This caused
"filter not found: min" crashes when posts had photos (never triggered
before the async iteration fix because photo arrays were always empty).

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@rmdes/indiekit-endpoint-activitypub",
-  "version": "2.0.19",
+  "version": "2.0.20",
   "description": "ActivityPub federation endpoint for Indiekit via Fedify. Adds full fediverse support: actor, inbox, outbox, followers, following, syndication, and Mastodon migration.",
   "keywords": [
     "indiekit",

views/partials/ap-item-media.njk

@@ -2,7 +2,7 @@
 
 {# Photo gallery with lightbox #}
 {% if item.photo and item.photo.length > 0 %}
-  {% set displayCount = [item.photo.length, 4] | min %}
+  {% set displayCount = item.photo.length if item.photo.length < 4 else 4 %}
   {% set extraCount = item.photo.length - 4 %}
   {% set totalPhotos = item.photo.length %}
   <div x-data="{ lightbox: false, idx: 0 }" class="ap-card__gallery ap-card__gallery--{{ displayCount }}">