Clarify export runtime copy

src/components/HelpDialog.vue

@@ -17,6 +17,7 @@ import {
 } from '@phosphor-icons/vue'
 import { Modal } from '@/components/ui'
 import { t } from '@/i18n'
+import { hasDesktopRender } from '@/lib/desktopRenderExport'
 
 const props = defineProps<{ modelValue: boolean }>()
 const emit = defineEmits<{ 'update:modelValue': [value: boolean] }>()
@@ -63,6 +64,9 @@ interface Chapter {
   titleKey: string
 }
 
+const isDesktop = !!window.ruwioDesktop
+const hasDesktopMp4 = hasDesktopRender()
+
 const CHAPTERS: Chapter[] = [
   {
     id: 'getting-started',
@@ -509,8 +513,16 @@ const CHAPTERS: Chapter[] = [
           { bodyKey: 'help.content.export.formats.runtime' },
           { bodyKey: 'help.content.export.formats.scene' },
           { bodyKey: 'help.content.export.formats.html' },
-          { bodyKey: 'help.content.export.formats.mp4' },
-          { bodyKey: 'help.content.export.formats.webm' },
+          {
+            bodyKey: hasDesktopMp4
+              ? 'help.content.export.formats.mp4Desktop'
+              : 'help.content.export.formats.mp4',
+          },
+          {
+            bodyKey: isDesktop
+              ? 'help.content.export.formats.webmDesktop'
+              : 'help.content.export.formats.webm',
+          },
         ],
       },
       {