fix: Rendering of translations based on the user's locale (#13211)

Previously, translations were generated and resolved purely based on the
account locale. This caused issues in multi-team, multi-region setups
where agents often work in different languages than the account default.

For example, an account might be set to English, while an agent prefers
Spanish. In this setup:
- Translations were always created using the account locale.
- Agents could not view content in their preferred language.
- This did not scale well for global teams.

There was also an issue with locale resolution during rendering, where
the system would incorrectly default to the account locale even when a
more appropriate locale should have been used.

With this update, During rendering, the system first attempts to use the
agent’s locale. If a translation for that locale does not exist, it
falls back to the account locale.


**How to test:**

- Set agent locale to a specific language (e.g., zh_CN) and account
language to en.
  - Translate a message.
- Verify translated content displays correctly for the agent's selected
locale
  - Do the same for another locale for agent.
- With multiple translations on a message (e.g., zh_CN, es, ml), verify
the UI shows the one matching agent's locale
- Change agent locale and verify the displayed translation updates
accordingly

app/javascript/dashboard/composables/useTranslations.js

@@ -1,4 +1,25 @@
 import { computed } from 'vue';
+import { useUISettings } from './useUISettings';
+import { useAccount } from './useAccount';
+
+/**
+ * Select translation based on locale priority.
+ * @param {Object} translations - Translations object with locale keys
+ * @param {string} agentLocale - Agent's preferred locale
+ * @param {string} accountLocale - Account's default locale
+ * @returns {string|null} Selected translation or null
+ */
+export function selectTranslation(translations, agentLocale, accountLocale) {
+  if (!translations || Object.keys(translations).length === 0) return null;
+
+  if (agentLocale && translations[agentLocale]) {
+    return translations[agentLocale];
+  }
+  if (accountLocale && translations[accountLocale]) {
+    return translations[accountLocale];
+  }
+  return translations[Object.keys(translations)[0]];
+}
 
 /**
  * Composable to extract translation state/content from contentAttributes.
@@ -6,6 +27,9 @@ import { computed } from 'vue';
  * @returns {Object} { hasTranslations, translationContent }
  */
 export function useTranslations(contentAttributes) {
+  const { uiSettings } = useUISettings();
+  const { currentAccount } = useAccount();
+
   const hasTranslations = computed(() => {
     if (!contentAttributes.value) return false;
     const { translations = {} } = contentAttributes.value;
@@ -14,8 +38,11 @@ export function useTranslations(contentAttributes) {
 
   const translationContent = computed(() => {
     if (!hasTranslations.value) return null;
-    const translations = contentAttributes.value.translations;
-    return translations[Object.keys(translations)[0]];
+    return selectTranslation(
+      contentAttributes.value.translations,
+      uiSettings.value?.locale,
+      currentAccount.value?.locale
+    );
   });
 
   return { hasTranslations, translationContent };