Theme timer ring colors green instead of hardcoded purple

CountdownCanvasView ring progress and track now use themed color
resources (md_color_ring_progress/md_color_ring_track) instead of
hardcoded Material3 purple, so they stay green in both light and dark mode.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

app/src/main/java/com/example/countdowntimer/CountdownCanvasView.kt

@@ -24,12 +24,12 @@ class CountdownCanvasView @JvmOverloads constructor(
         isFakeBoldText = false
     }
     private val ringPaint = Paint(Paint.ANTI_ALIAS_FLAG).apply {
-        color = Color.parseColor("#6750A4")
+        color = ContextCompat.getColor(context, R.color.md_color_ring_progress)
         style = Paint.Style.STROKE
         strokeWidth = 16f
     }
     private val ringBgPaint = Paint(Paint.ANTI_ALIAS_FLAG).apply {
-        color = Color.parseColor("#D0BCFF")
+        color = ContextCompat.getColor(context, R.color.md_color_ring_track)
         style = Paint.Style.STROKE
         strokeWidth = 16f
     }

app/src/main/res/values-night/colors.xml

@@ -2,4 +2,6 @@
 <resources>
     <color name="color_gradient_start">#1B3A1B</color>
     <color name="color_gradient_end">#0D1F0D</color>
+    <color name="md_color_ring_progress">#A5D6A7</color>
+    <color name="md_color_ring_track">#2E7D32</color>
 </resources>

app/src/main/res/values-night/themes.xml

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
     <color name="md_theme_dark_primary">#A5D6A7</color>
+    <color name="md_theme_dark_primaryContainer">#2E7D32</color>
     <color name="md_theme_dark_secondary">#869F7C</color>
 
     <style name="Theme.CountdownTimer" parent="Theme.Material3.DayNight.NoActionBar">

app/src/main/res/values/colors.xml

@@ -3,4 +3,6 @@
     <color name="color_gradient_start">#E8F5E9</color>
     <color name="color_gradient_end">#C8E6C9</color>
     <color name="color_icon_tint">#2E7D32</color>
+    <color name="md_color_ring_progress">#2E7D32</color>
+    <color name="md_color_ring_track">#81C784</color>
 </resources>