Add height and width attributes to ballot cover images (#457)

This prevents layout shift on the ballot page.

Fixes #453

Author: dfabulich

IFComp/lib/IFComp/Schema/Result/Entry.pm

@@ -930,6 +930,15 @@ sub cover_exists {
     }
 }
 
+sub cover_image {
+    my $self = shift;
+
+    return 0 unless $self->cover_exists;
+
+    my $image = Imager->new( file => $self->web_cover_file );
+    return $image;
+}
+
 sub create_web_cover_file {
     my $self = shift;
 

IFComp/root/src/_current_entry_row.tt

@@ -3,7 +3,7 @@
     [% IF entry.cover_exists %]
     <div class="col-sm-4">
         <div itemprop="image" itemscope itemtype="https://schema.org/ImageObject">
-            <a itemprop="contentUrl" href="[% c.uri_for_action( '/play/full_cover', [ entry.id ] ) %]" target="_blank"><img itemprop="thumbnailUrl" class="img-fluid" src="[% c.uri_for_action( '/play/cover', [ entry.id ] ) %]" alt="Cover art for [% entry.title %]" loading="lazy"></a>
+            <a itemprop="contentUrl" href="[% c.uri_for_action( '/play/full_cover', [ entry.id ] ) %]" target="_blank"><img itemprop="thumbnailUrl" class="img-fluid" src="[% c.uri_for_action( '/play/cover', [ entry.id ] ) %]" alt="Cover art for [% entry.title %]" height="[% entry.cover_image.getheight %]" width="[% entry.cover_image.getwidth %]" loading="lazy"></a>
 	    [% IF (entry.genai_state / 2) % 2 == 1 %]
 		<span style="font-size: smaller;" itemprop="genai_cover"><em>Generative artificial intelligence was used to make this cover art.</em></span>
 	    [% END %]