refactor: clean up redundant calls and replace deprecated APIs

Unnecessary safe call on a non-null File receiver; unused catch parameters renamed to _; constructor parameter used only in init no longer held as a property; deprecated Configuration.screenHeightDp replaced with LocalWindowInfo.containerSize; redundant filterNotNull on Paging items; deprecated invisibleToUser() replaced with hideFromAccessibility(); redundant alias variable inlined; redundant else in an exhaustive when removed; paging snapshot read moved into the SideEffect that consumes it.

app/src/main/java/com/example/research/MainActivity.kt

@@ -181,7 +181,7 @@ class MainActivity : ComponentActivity() {
             runBlocking {
                 app.preferencesManager.hadNoDictionaries.first()
             }
-        } catch (e: Exception) {
+        } catch (_: Exception) {
             true
         }
     }