App 2.31.0: full screen from the navigation, swipe in from the left to return

The Overview's full-screen button moved from the page's corner into the
navigation, beside the MG4 logo. A swipe in from the left edge (EdgeSwipe,
unit-tested) brings the navigation back; a faint handle marks the edge.
Sideways swipes no longer change the page: only the navigation does.

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 127
-        versionName "2.30.0"
+        versionCode 128
+        versionName "2.31.0"
 
         // 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.