refactor(post-events): read event data from resolved calendarItem

Replace direct post.isEvent/eventDate/eventLocation reads with
getPostEventInfo() helper that derives info from the resolved
calendarItem reference. Loaders now resolve "calendarItem" and request
that field instead of legacy flat properties.

Also regenerate iconify mdi subset (map-marker-outline, download,
google, calendar-search, refresh).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/lib/components/PostCard.svelte

@@ -6,6 +6,7 @@
   import EventBadges from "./EventBadges.svelte";
   import RustyImage from "./RustyImage.svelte";
   import Card from "./Card.svelte";
+  import { getPostEventInfo } from "$lib/blog-utils";
   import { useTranslate, T } from "$lib/translations";
 
   const t = useTranslate();
@@ -33,15 +34,9 @@
   const focal = $derived(post._imageFocal ?? null);
   const fallbackImg = $derived(post._resolvedImageUrl);
 
-  type PostWithEvent = PostWithImage & {
-    isEvent?: boolean;
-    eventDate?: string;
-    eventLocation?: { text?: string };
-  };
-  const p = $derived(post as PostWithEvent);
-
-  const eventDate = $derived(p.isEvent && p.eventDate ? p.eventDate : null);
-  const locationText = $derived(p.eventLocation?.text ?? null);
+  const eventInfo = $derived(getPostEventInfo(post));
+  const eventDate = $derived(eventInfo.eventDate);
+  const locationText = $derived(eventInfo.eventLocation?.text ?? null);
 
   const tagSlugs = $derived(
     (post.postTag ?? []).map((t) =>
@@ -50,7 +45,7 @@
   );
   const hasTerminTag = $derived(tagSlugs.includes("tag-termin"));
   const isPastEvent = $derived(
-    hasTerminTag && !!p.eventDate && new Date(p.eventDate).getTime() < Date.now(),
+    hasTerminTag && !!eventDate && new Date(eventDate).getTime() < Date.now(),
   );
 </script>