Simplify created_at to an integer

We don’t facet on this so we can save a lot of bytes per record on this

app/indices/typesense_base_index.rb

@@ -4,11 +4,7 @@ class TypesenseBaseIndex < Typesensual::Index
   schema do
     enable_nested_fields
 
-    field 'created_at', type: 'object'
-    field 'created_at.year', type: 'int32', facet: true, optional: true
-    field 'created_at.month', type: 'int32', facet: true, optional: true
-    field 'created_at.day', type: 'int32', facet: true, optional: true
-    field 'created_at.timestamp', type: 'int64', optional: true
+    field 'created_at', type: 'int32', optional: true
   end
 
   private

app/indices/typesense_manga_index.rb

@@ -60,7 +60,7 @@ def index(ids)
         genres: manga.genres.ids,
         chapter_count: manga.chapter_count,
         volume_count: manga.volume_count,
-        created_at: format_date(manga.created_at)
+        created_at: manga.created_at.to_i
       }.compact)
     end
   end

app/indices/typesense_users_index.rb

@@ -42,7 +42,7 @@ def index(ids)
           past_names: user.past_names || [],
           slug: user.slug,
           followers_count: user.followers_count,
-          created_at: format_date(user.created_at)
+          created_at: user.created_at.to_i
         }.compact)
       end
     end