refactor: improve i18n and security in upgrade modal components

- Use proper i18n keys (g.learnMore, subscription.required.subscribe)
- Add rel="noopener noreferrer" to external link for security
- Remove empty script block from UploadModelUpgradeModalBody

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: luke-mino-altherr

src/platform/assets/components/UploadModelUpgradeModalBody.vue

@@ -7,5 +7,3 @@
     </p>
   </div>
 </template>
-
-<script setup lang="ts"></script>

src/platform/assets/components/UploadModelUpgradeModalFooter.vue

@@ -3,10 +3,11 @@
     <a
       href="https://blog.comfy.org/p/comfy-cloud-new-features-and-pricing"
       target="_blank"
+      rel="noopener noreferrer"
       class="text-muted-foreground mr-auto underline flex items-center gap-2"
     >
       <i class="icon-[lucide--external-link]" />
-      <span>{{ $t('Learn more') }}</span>
+      <span>{{ $t('g.learnMore') }}</span>
     </a>
     <TextButton
       :label="$t('g.close')"
@@ -15,7 +16,7 @@
       @click="emit('close')"
     />
     <TextButton
-      :label="$t('Subscribe')"
+      :label="$t('subscription.required.subscribe')"
       type="secondary"
       size="md"
       @click="emit('subscribe')"