Tasks: square the remaining checkboxes I missed (Today timeline, Next-3, Matrix rows)

Follow-up after the first pass only caught the list-style rows. Converted the
actual tap-to-complete toggles + markers that were still circular:
- Today timeline (tlRows): marker complete/all-day → rounded square (circleD
  18→16); trailing SF-symbol toggle → rounded-square checkbox.
- Today Next-3-Days row: 20pt circle → 16pt rounded square.
- Today "Completed Today" row indicator: green circle → green rounded square.
- Calendar Month agenda (DayTimelineView): trailing SF-symbol toggle → square.
- Matrix quadrant row checkbox: circles → rounded squares.

Left intentionally circular: multi-select sheet (selection, not completion) and
workout-set checkboxes (separate domain).

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

KisaniCal/Views/CalendarView.swift

@@ -1950,9 +1950,19 @@ private struct DayTLRow: View {
                 Spacer(minLength: 0)
                 if let toggle = onToggle {
                     Button(action: toggle) {
-                        Image(systemName: entry.isComplete ? "checkmark.circle.fill" : "circle")
+                        ZStack {
-                            .font(.system(size: 18))
+                            RoundedRectangle(cornerRadius: 5, style: .continuous)
-                            .foregroundColor(entry.isComplete ? entry.color : AppColors.text3(cs))
+                                .fill(entry.isComplete ? entry.color : Color.clear)
+                                .frame(width: 16, height: 16)
+                            RoundedRectangle(cornerRadius: 5, style: .continuous)
+                                .strokeBorder(entry.isComplete ? Color.clear : AppColors.text3(cs), lineWidth: 1.5)
+                                .frame(width: 16, height: 16)
+                            if entry.isComplete {
+                                Image(systemName: "checkmark")
+                                    .font(.system(size: 9, weight: .bold))
+                                    .foregroundColor(.white)
+                            }
+                        }
                     }
                     .buttonStyle(.plain)
                 } else if onWorkoutTap != nil {

KisaniCal/Views/MatrixView.swift

@@ -261,12 +261,12 @@ struct QuadrantCard: View {
                     Color.clear.frame(height: 0).trackScrollForTabBar()
                     ForEach(tasks) { task in
                         HStack(alignment: .top, spacing: 8) {
-                            // Circle checkbox
+                            // Rounded-square checkbox
                             ZStack {
-                                Circle()
+                                RoundedRectangle(cornerRadius: 5, style: .continuous)
                                     .fill(task.isComplete ? badgeColor.opacity(0.15) : badgeBg)
                                     .frame(width: 16, height: 16)
-                                Circle()
+                                RoundedRectangle(cornerRadius: 5, style: .continuous)
                                     .stroke(task.isComplete ? badgeColor.opacity(0.4) : badgeColor, lineWidth: 1.5)
                                     .frame(width: 16, height: 16)
                                 if task.isComplete {

KisaniCal/Views/TodayView.swift

@@ -486,7 +486,7 @@ private struct TodayTLRow: View {
 
     @AppStorage("todayShowDetails") private var showDetails = true
 
-    private let circleD: CGFloat = 18
+    private let circleD: CGFloat = 16
     private let timeW:   CGFloat = 46
     private let trackW:  CGFloat = 26
     private let topGap:  CGFloat = 10
@@ -520,14 +520,14 @@ private struct TodayTLRow: View {
                 // Marker
                 ZStack {
                     if entry.isComplete {
-                        Circle()
+                        RoundedRectangle(cornerRadius: 5, style: .continuous)
                             .fill(entry.color.opacity(0.14))
                             .frame(width: circleD, height: circleD)
                         Image(systemName: "checkmark")
                             .font(.system(size: 7.5, weight: .bold))
                             .foregroundColor(entry.color)
                     } else if entry.isAllDay {
-                        Circle()
+                        RoundedRectangle(cornerRadius: 5, style: .continuous)
                             .strokeBorder(entry.color, lineWidth: 1.5)
                             .frame(width: circleD, height: circleD)
                     } else {
@@ -565,9 +565,19 @@ private struct TodayTLRow: View {
                     bg: entry.task.quadrant.softColor
                 )
                 Button(action: onToggle) {
-                    Image(systemName: entry.isComplete ? "checkmark.circle.fill" : "circle")
+                    ZStack {
-                        .font(.system(size: 20))
+                        RoundedRectangle(cornerRadius: 5, style: .continuous)
-                        .foregroundColor(entry.isComplete ? entry.color : AppColors.text3(cs))
+                            .fill(entry.isComplete ? entry.color : Color.clear)
+                            .frame(width: 16, height: 16)
+                        RoundedRectangle(cornerRadius: 5, style: .continuous)
+                            .strokeBorder(entry.isComplete ? Color.clear : AppColors.text3(cs), lineWidth: 1.5)
+                            .frame(width: 16, height: 16)
+                        if entry.isComplete {
+                            Image(systemName: "checkmark")
+                                .font(.system(size: 9, weight: .bold))
+                                .foregroundColor(.white)
+                        }
+                    }
                 }
                 .buttonStyle(.plain)
             }
@@ -639,9 +649,9 @@ struct OverdueCard: View {
                 ForEach(tasks) { task in
                     HStack(spacing: 10) {
                         Button { withAnimation(KisaniSpring.bounce) { onToggle(task) } } label: {
-                            Circle()
+                            RoundedRectangle(cornerRadius: 5, style: .continuous)
-                                .stroke(AppColors.red, lineWidth: 1.5)
+                                .strokeBorder(AppColors.red, lineWidth: 1.5)
-                                .frame(width: 20, height: 20)
+                                .frame(width: 16, height: 16)
                                 .frame(width: 36, height: 44)
                                 .contentShape(Rectangle())
                         }
@@ -1159,9 +1169,14 @@ struct CompletedTodaySection: View {
 
                 ForEach(tasks) { task in
                     HStack(spacing: 10) {
-                        Image(systemName: "checkmark.circle.fill")
+                        ZStack {
-                            .font(.system(size: 18))
+                            RoundedRectangle(cornerRadius: 5, style: .continuous)
-                            .foregroundColor(AppColors.green)
+                                .fill(AppColors.green)
+                                .frame(width: 16, height: 16)
+                            Image(systemName: "checkmark")
+                                .font(.system(size: 9, weight: .bold))
+                                .foregroundColor(.white)
+                        }
                         .frame(width: 36, height: 44)
 
                         VStack(alignment: .leading, spacing: 1) {