Minamp 1.6: adjustable UI size, larger text and controls

- New setting "Text and button size" (Normal / Large / Extra large): scales
  text, icons and buttons on top of the phone's density (App.UI_SCALES)
- Larger default text, rows, tiles, touch targets and player icons; all sizes
  now live in res/values/dimens.xml
- Seek bar knob drawn in code, since Android 2.x caches XML shapes at the
  size they were first loaded
- Full-width buttons wrap to two lines instead of cutting words off
- Shorter labels so they fit 240x320 screens in both languages
- tools/check_fit.py checks that UI texts fit their slots at every size and
  language using Droid Sans metrics; build.sh runs it and setup_toolchain.sh
  fetches the font

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

res/layout/row_header.xml

@@ -4,8 +4,8 @@
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
     android:paddingLeft="10dp"
-    android:paddingTop="12dp"
-    android:paddingBottom="4dp"
+    android:paddingTop="14dp"
+    android:paddingBottom="6dp"
     android:textColor="@color/accent"
-    android:textSize="11sp"
+    android:textSize="@dimen/text_small"
     android:textStyle="bold" />