refactor: convert from Android TV to phone/tablet mode

- Replace Theme.Leanback with Theme.AppCompat.DayNight.NoActionBar
- Remove leanback dependencies (leanback, leanback-preference)
- Remove LEANBACK_LAUNCHER, leanback feature, banner from manifest
- PlayerActivity: replace D-pad with touch controls (click to toggle episodes, close button)
- SearchFragment: adaptive grid (3 cols phone / 5 cols tablet), remove focus-based history toggle
- Fix deprecated adapterPosition -> bindingAdapterPosition

app/src/main/java/com/videoapp/tv/ui/SearchFragment.kt

@@ -77,7 +77,8 @@ class SearchFragment : Fragment() {
     }
 
     private fun setupResultsGrid() {
-        resultsGrid.layoutManager = GridLayoutManager(context, 4)
+        val spanCount = if (resources.configuration.screenWidthDp >= 600) 5 else 3
+        resultsGrid.layoutManager = GridLayoutManager(context, spanCount)
         resultsGrid.adapter = adapter
     }
 
@@ -107,12 +108,6 @@ class SearchFragment : Fragment() {
                 showHistory(emptyList())
             }
         }
-
-        searchInput.setOnFocusChangeListener { _, hasFocus ->
-            if (hasFocus) {
-                historyContainer.visibility = View.VISIBLE
-            }
-        }
     }
 
     private fun performSearch(keyword: String) {