Workout check-in: missed state + rest-day compensation (KC-16)

- Notification actions on workout reminders/check-ins: "Yes, I completed
  it", "No, I didn't" (marks the day missed, then asks to compensate on a
  rest day), "Remind me in 1 hour" (snooze).
- VM: missedDates + compensations (persisted/synced), per-date
  markWorkoutDone/Missed, workoutStatus, upcomingRestDays,
  scheduleCompensation, promptCompensation, checkPendingMissed.
  program(for:) returns a compensation program on its rest day.
- CompensationSheet: pick a rest day or keep as missed; compensation days
  get a one-off "Missed workout recovery" reminder.
- Long-press menus: workout row (Done / Not Done / Compensate) in Today +
  Calendar; exercise cards (Mark as Done / Not Done). All actions are
  per-date — one occurrence never affects another.
- Workout row shows Pending / Done / Missed + "Compensation" label.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

KisaniCal/Views/WorkoutView.swift

@@ -161,6 +161,17 @@ struct WorkoutView: View {
                                             UIImpactFeedbackGenerator(style: .medium).impactOccurred()
                                         }
                                         .contextMenu {
+                                            Button {
+                                                withAnimation { vm.setExerciseDone(sectionId: section.id, exerciseId: ex.id, done: true) }
+                                            } label: {
+                                                Label("Mark as Done", systemImage: "checkmark.circle")
+                                            }
+                                            Button {
+                                                withAnimation { vm.setExerciseDone(sectionId: section.id, exerciseId: ex.id, done: false) }
+                                            } label: {
+                                                Label("Mark as Not Done", systemImage: "circle")
+                                            }
+                                            Divider()
                                             Button(role: .destructive) {
                                                 withAnimation { vm.deleteExercise(sectionId: section.id, exerciseId: ex.id) }
                                             } label: {
@@ -762,6 +773,88 @@ struct WorkoutHistoryView: View {
     }
 }
 
+// MARK: - Compensation Sheet ("missed → make it up on a rest day")
+struct CompensationSheet: View {
+    let missed: WorkoutViewModel.MissedDay
+    @EnvironmentObject var vm: WorkoutViewModel
+    @Environment(\.colorScheme) var cs
+    @Environment(\.dismiss) var dismiss
+
+    private let dayFmt: DateFormatter = {
+        let f = DateFormatter(); f.dateFormat = "EEEE, MMM d"; return f
+    }()
+
+    private var restDays: [Date] { vm.upcomingRestDays() }
+
+    var body: some View {
+        VStack(spacing: 0) {
+            VStack(spacing: 6) {
+                Image(systemName: "arrow.uturn.forward.circle")
+                    .font(.system(size: 30, weight: .light))
+                    .foregroundColor(AppColors.accent)
+                Text("Missed: \(missed.programName)")
+                    .font(AppFonts.sans(17, weight: .bold)).foregroundColor(AppColors.text(cs))
+                Text("Do you want to compensate for this workout on a rest day?")
+                    .font(AppFonts.sans(12)).foregroundColor(AppColors.text3(cs))
+                    .multilineTextAlignment(.center).padding(.horizontal, 24)
+            }
+            .padding(.top, 24).padding(.bottom, 16)
+
+            Divider().background(AppColors.border(cs))
+
+            if restDays.isEmpty {
+                Text("No free rest days in the next two weeks.")
+                    .font(AppFonts.sans(12)).foregroundColor(AppColors.text3(cs))
+                    .frame(maxWidth: .infinity).padding(.vertical, 30)
+            } else {
+                ScrollView(showsIndicators: false) {
+                    VStack(spacing: 0) {
+                        ForEach(restDays, id: \.self) { day in
+                            Button {
+                                if let pid = missed.programId {
+                                    vm.scheduleCompensation(programId: pid, on: day)
+                                }
+                                dismiss()
+                            } label: {
+                                HStack {
+                                    Image(systemName: "moon.zzz")
+                                        .font(.system(size: 13)).foregroundColor(AppColors.accent)
+                                        .frame(width: 28)
+                                    Text(dayFmt.string(from: day))
+                                        .font(AppFonts.sans(14)).foregroundColor(AppColors.text(cs))
+                                    Spacer()
+                                    Text("COMPENSATE")
+                                        .font(AppFonts.mono(8.5, weight: .bold))
+                                        .foregroundColor(AppColors.accent)
+                                        .padding(.horizontal, 8).padding(.vertical, 4)
+                                        .background(AppColors.accentSoft).clipShape(Capsule())
+                                }
+                                .padding(.horizontal, 18).padding(.vertical, 13)
+                            }
+                            .buttonStyle(.plain)
+                            if day != restDays.last { Divider().background(AppColors.border(cs)).padding(.leading, 46) }
+                        }
+                    }
+                }
+            }
+
+            Spacer(minLength: 0)
+
+            Button { dismiss() } label: {
+                Text("No, keep as missed")
+                    .font(AppFonts.sans(14, weight: .semibold))
+                    .foregroundColor(AppColors.text2(cs))
+                    .frame(maxWidth: .infinity).padding(13)
+                    .background(AppColors.surface2(cs))
+                    .clipShape(RoundedRectangle(cornerRadius: AppRadius.large))
+            }
+            .buttonStyle(.plain)
+            .padding(.horizontal, 20).padding(.bottom, 20).padding(.top, 8)
+        }
+        .background(AppColors.background(cs).ignoresSafeArea())
+    }
+}
+
 // MARK: - Rest Day Card
 struct RestDayCard: View {
     @Environment(\.colorScheme) private var cs