Return from files to explorer

app/androidApp/src/main/kotlin/com/example/aiapp/FilesScreen.kt

@@ -81,9 +81,9 @@ private enum class UnsavedDestination {
  * The files on the machine a session runs on: browse them, read one, change one.
  *
  * Drawn **over** the session rather than instead of it (see [AppRoot]), so its event stream keeps
- * flowing and coming back from a file costs nothing. Android back returns from a file to its
- * directory, then walks up the directory tree. The header's back button closes the explorer and
- * returns directly to the session.
+ * flowing and coming back from a file costs nothing. Both back controls return from a file to its
+ * directory. In a directory, Android back walks up the directory tree while the header's back
+ * button closes the explorer and returns to the session.
  *
  * Every directory that has been visited is kept for as long as this is open; the refresh glyph is
  * how one gets asked again on purpose, and creating something refetches the directory it was
@@ -194,7 +194,7 @@ fun FilesScreen(settings: ServerSettings, target: FilesTarget, onClose: () -> Un
                         editing = editing,
                         onEditing = { editing = it },
                         onDirty = { dirty = it },
-                        onBack = { leave(UnsavedDestination.Session) },
+                        onBack = { leave(UnsavedDestination.Directory) },
                     )
             }
         }