fix(i18n): track system language on every launch instead of caching first-seen value in localStorage

src/app/i18n.ts

@@ -24,6 +24,19 @@ i18n
     // PushStrings / SW normalizeLang clamp — all three surfaces live in
     // the same `{en, ru}` set.
     supportedLngs: ['en', 'ru'],
+    // Track the device/system language on every launch. The default
+    // detector order checks localStorage before navigator.language, so
+    // i18next "sticks" to whichever language was picked on first install
+    // — when a user later changes their phone's system language, the
+    // cached value wins and the app stays in the old language. Vojo has
+    // no in-app language selector, so we have nothing to cache: read
+    // `navigator.language` every time, fall through to `htmlTag` for
+    // edge cases (extension iframes, very old WebViews), and write
+    // nothing back to storage.
+    detection: {
+      order: ['navigator', 'htmlTag'],
+      caches: [],
+    },
     interpolation: {
       escapeValue: false, // not needed for react as it escapes by default
     },