feat: add i18n framework with Indonesian translation support (#124)

* feat: add i18n support with separate translation files

- Extract translations from store.js to separate files for easier management
- Add translation files for English (en.js), Indonesian (id.js), Turkish (tr.js), and Chinese (zh.js)
- Load translations via window.translations object before Alpine store initialization
- Add Bahasa Indonesia option to language selector

* feat: translate remaining hardcoded UI strings

- Update index.html to use t() for Menu and GitHub labels
- Update views to translate Tier, Quota, Live, tier badges, and close button
- Update components to use translated error messages and confirmation dialogs
- Update utils to use translated validation and error messages
- Update app-init.js to use translated OAuth success/error messages

public/js/utils/model-config.js

@@ -26,7 +26,7 @@ window.ModelConfigUtils.updateModelConfig = async function(modelId, configUpdate
         }
 
         if (!response.ok) {
-            throw new Error('Failed to update model config');
+            throw new Error(store.t('failedToUpdateModelConfig'));
         }
 
         // Optimistic update of local state
@@ -38,5 +38,5 @@ window.ModelConfigUtils.updateModelConfig = async function(modelId, configUpdate
 
         // Recompute quota rows to reflect changes
         dataStore.computeQuotaRows();
-    }, 'Failed to update model config');
+    }, Alpine.store('global').t('failedToUpdateModelConfig'));
 };