App 2.27.0: full-width Overview, a button hides the navigation

A small button in the Overview's top-right corner hides the app's
sidebar (or bottom bar) and brings it back; only on the Overview,
remembered, swiping still works. Emulator only.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LhzAVaUyqcw5PkGjz4mWW6

app/build.gradle

@@ -34,8 +34,8 @@ android {
         applicationId "com.stinnesbeck.nilsmg4"
         minSdk 27
         targetSdk 36
-        versionCode 120
-        versionName "2.26.0"
+        versionCode 121
+        versionName "2.27.0"
 
         // Nothing about the server ships in the APK: its URL and ingest token are entered in
         // the app's Server tab (ServerConfig), and the database is only reachable by the server.