MiniABS 1.5: Audiobookshelf icon and purple theme

- Launcher icon from the Audiobookshelf icon pack (art/icon_master_512.png),
  including an xhdpi size
- Notification icon cut out of the same artwork; player icons redrawn in the
  icon's lilac (tools/make_icons.py)
- Purple colour scheme taken from the icon: gradient accent buttons, lilac
  text accents (accent_light), purple-tinted backgrounds
- README: where the icon and colours come from

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

res/values/values.xml

@@ -2,16 +2,20 @@
 <resources>
     <string name="app_name">MiniABS</string>
 
-    <color name="bg">#121519</color>
-    <color name="surface">#1C2127</color>
-    <color name="header">#0B0D10</color>
-    <color name="line">#2A3038</color>
-    <color name="text">#ECEFF2</color>
-    <color name="sub">#A9B2BC</color>
-    <color name="dim">#6E7882</color>
-    <color name="accent">#F5A623</color>
+    <!-- Colours taken from the Audiobookshelf icon: gradient #9437FC to #570DCF, waves #BC8AFC -->
+    <color name="bg">#13111A</color>
+    <color name="surface">#1D1928</color>
+    <color name="header">#0C0A12</color>
+    <color name="line">#2C2638</color>
+    <color name="text">#EEEBF3</color>
+    <color name="sub">#ADA6BC</color>
+    <color name="dim">#736C82</color>
+    <color name="accent">#7A25EC</color>        <!-- fills: tabs, progress, seek bar -->
+    <color name="accent_light">#BC8AFC</color>  <!-- text and small marks on dark backgrounds -->
+    <color name="accent_top">#9437FC</color>    <!-- button gradient, as in the icon -->
+    <color name="accent_bottom">#5A11D3</color>
     <color name="fresh">#6EC1E4</color>
-    <color name="pressed">#2C333C</color>
+    <color name="pressed">#2E2642</color>
 
     <style name="MiniTheme" parent="@android:style/Theme.NoTitleBar">
         <item name="android:windowBackground">@color/bg</item>