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/drawable/seek_progress.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <layer-list xmlns:android="http://schemas.android.com/apk/res/android">
-    <item android:id="@android:id/background"><shape><solid android:color="#40FFFFFF" /><corners android:radius="2dp" /><size android:height="4dp" /></shape></item>
+    <item android:id="@android:id/background"><shape><solid android:color="#40FFFFFF" /><corners android:radius="3dp" /><size android:height="@dimen/seek_track" /></shape></item>
     <item android:id="@android:id/secondaryProgress"><clip><shape><solid android:color="#40FFFFFF" /><corners android:radius="2dp" /></shape></clip></item>
     <item android:id="@android:id/progress"><clip><shape><solid android:color="@color/text" /><corners android:radius="2dp" /></shape></clip></item>
 </layer-list>