feat(ui): map as 4th bottom-nav tab, passes top bar restored to upstream layout, bigger QSO expand arrow

- Map moves from the passes-page top-right button to the bottom navigation
  bar at position 4 from the left (Satellites, Passes, AMSAT, Map, Mutual,
  Settings), matching the upstream nav order.
- Passes top bar restored to the original repo layout: left = radios dialog
  (ic_radios), right = passes filter/schedule dialog (ic_filter) — the map
  button is gone from the top bar.
- Worked-grid QSO dialog expand arrow enlarged from bodySmall to 18sp.

feature/map/src/main/java/com/rtbishop/look4sat/feature/map/MapScreen.kt

@@ -389,7 +389,7 @@ private fun WorkedGridCallRow(
             )
             Text(
                 text = if (expanded) " ▴" else " ▾",
-                style = MaterialTheme.typography.bodySmall,
+                fontSize = 18.sp,
                 color = MaterialTheme.colorScheme.primary
             )
         }