fix: recreate activity when language changes

AppCompatDelegate.setApplicationLocales() does not reliably recreate the
running activity across all Android versions. Add an explicit recreate()
call after persisting the locale so the UI reloads in the new language
immediately.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: nichu42

app/src/main/java/de/nichu42/boxviewer/util/LocaleHelper.kt

@@ -1,6 +1,8 @@
 package de.nichu42.boxviewer.util
 
+import android.app.Activity
 import android.content.Context
+import android.content.ContextWrapper
 import androidx.appcompat.app.AppCompatDelegate
 import androidx.core.os.LocaleListCompat
 import de.nichu42.boxviewer.R
@@ -45,7 +47,8 @@ object LocaleHelper {
     }
 
     /**
-     * Persists the user's choice and applies it immediately.
+     * Persists the user's choice, applies it immediately, and recreates the
+     * current activity so the new locale is visible right away.
      *
      * @param tag Empty string means "follow system default"; otherwise a BCP-47 tag
      *            from [SUPPORTED_LOCALES].
@@ -56,6 +59,7 @@ object LocaleHelper {
             .putString(KEY_APP_LANGUAGE, tag)
             .apply()
         applyLocale(tag)
+        context.findActivity()?.recreate()
     }
 
     /** Returns the saved language tag, or empty string for system default. */
@@ -79,4 +83,14 @@ object LocaleHelper {
         }
         AppCompatDelegate.setApplicationLocales(localeList)
     }
+
+    /** Walks up the [ContextWrapper] chain to find the hosting [Activity]. */
+    private fun Context.findActivity(): Activity? {
+        var currentContext = this
+        while (currentContext is ContextWrapper) {
+            if (currentContext is Activity) return currentContext
+            currentContext = currentContext.baseContext
+        }
+        return null
+    }
 }