Widgets: bars countdown widget + unified slate/orange theme (KC-15)

- New EventBarsWidget ("Event Countdown (Bars)") using BarGrid + EventBarsView,
  with a fine "X hr, Y min left" label; registered in the bundle.
- Re-themed every home-screen widget to the shared WidgetTheme (dark slate
  background + brand orange): Day Progress, Tasks Done Today, Event Countdown
  (dots), My Tasks. Lock-screen widgets keep .thinMaterial (system-tinted).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

KisaniCalWidgets/KisaniCalWidgets.swift

@@ -40,7 +40,7 @@ struct DayProgressWidget: Widget {
     let kind = "KisaniDayProgress"
     var body: some WidgetConfiguration {
         StaticConfiguration(kind: kind, provider: KisaniProvider()) { _ in
-            ProgressDotView(period: .day, accent: Color(red: 0.48, green: 0.87, blue: 0.80))
+            ProgressDotView(period: .day, accent: WidgetTheme.accent)
         }
         .configurationDisplayName("Day Progress")
         .description("How much of today has elapsed, as a dot grid.")
@@ -106,6 +106,7 @@ struct LockScreenCircularWidget: Widget {
 struct KisaniWidgetBundle: WidgetBundle {
     var body: some Widget {
         EventCountdownWidget()
+        EventBarsWidget()
         MyTasksWidget()
         DayProgressWidget()
         TasksCompleteWidget()