web/build: merge i18n chunks for each language into one file

web/vite.config.ts

@@ -5,6 +5,20 @@ export default defineConfig({
     plugins: [
         sveltekit()
     ],
+    build: {
+        rollupOptions: {
+            output: {
+                manualChunks: (id) => {
+                    if (id.includes('/web/i18n')) {
+                        const lang = id.split('/web/i18n/')?.[1].split('/')?.[0];
+                        if (lang) {
+                            return `i18n_${lang}`;
+                        }
+                    }
+                }
+            }
+        }
+    },
     server: {
         fs: {
             allow: [