workout: fix iCloud sync stomping the Watch-logged streak, remove Undo (KC-67)

Root cause: CloudSyncManager.kvStoreChanged blindly overwrote any
externally-changed iCloud key, including workoutDates - a lifetime
tally that every local write path (HealthKit sync, manual finish)
carefully dedups/unions. A stale iCloud snapshot racing a fresh
Watch-sync write could silently replace the correct array with an
older, smaller one. Now unions instead of overwriting for that key
specifically.

Also: removed the Undo action/row from DotProgressCard entirely (Watch/
Health is the source of truth once a day is logged), and restored the
confirmation dialog on Finish Workout so every state-changing action
confirms first.

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

KisaniCal/ISSUES.md

@@ -2348,3 +2348,59 @@ Not build-verified (no iOS runtime here). Self-reviewed: balanced braces/
 parens confirmed per-file. Same caveat as KC-65: tasks created before that
 fix still have no real `createdAt` and fall through to the anchor/inferred
 heuristics in both widgets.
+
+## KC-67 — Watch/Health workout streak got stomped by a stale iCloud sync
+
+Status: Implemented (not build-verified — no iOS runtime here)
+Reported by: User — streak reset to 3 after a workout was already logged
+by the Watch, plus a request for Finish/Clear-All confirmations and to
+remove Undo
+Area: Workout (`DotProgressCard`, `WorkoutViewModel`, `CloudSyncManager`)
+
+### Root cause
+`workoutDates` is a lifetime tally (KC-40 — `Set(workoutDates).count`,
+append-only by design) and every local write path already respects that:
+`logWorkoutCompleted` dedups by key before appending, `syncFromHealthKit`
+only unions HealthKit's dates in. But `CloudSyncManager.kvStoreChanged` —
+the handler for "iCloud KV store changed externally" — did a **blind
+overwrite**: `UserDefaults.kisani.set(val, forKey: key)` for every changed
+key, no merge. Since `save()` pushes `workoutDates` to iCloud on every
+write (including the Watch/HealthKit sync path), a stale iCloud snapshot
+arriving after a fresh local write (races are inherent to `NSUbiquitous
+KeyValueStore` — it's eventually consistent) would silently replace the
+correct, larger local array with an older, smaller one — exactly matching
+"the workout was already logged by the Watch, then tapping Finish reset
+the streak."
+
+### Change
+- `CloudSyncManager.kvStoreChanged`: for keys matching
+  `kisani.workout.completedDates.*`, union the incoming iCloud value with
+  whatever's already local instead of overwriting — an external change can
+  now only ever add days, never erase ones this device already knows
+  about. Every other synced key keeps the existing overwrite behavior
+  (unaffected — this tally is the only append-only-by-design value among
+  them).
+- `DotProgressCard`: removed the `onUndo` action, its row, and the
+  `isDoneToday`/`isMissedToday` branch that showed it — the done/missed
+  state now shows the status header + progress dots with no action row
+  underneath at all (per "remove the Undo action from the logged workout
+  state"). Watch/Health is the source of truth once a day is logged;
+  there's no in-card way to contest that.
+- Removed `onUndo:` at the `DotProgressCard(...)` call site in
+  `WorkoutView.swift`, and deleted `WorkoutViewModel.unmarkWorkoutDone`/
+  `unmarkWorkoutMissed` (now dead — Undo was their only caller).
+- Re-added the confirmation dialog on "Finish Workout" (previously
+  reverted in KC-63's follow-up at the user's request; re-requested here
+  alongside the streak fix) — every state-changing action on the card
+  (Finish, Check All, Clear All, Didn't Train) now confirms first.
+
+Files: `KisaniCal/Managers/CloudSyncManager.swift`,
+`KisaniCal/Views/WorkoutView.swift`, `KisaniCal/Models/ExerciseModels.swift`.
+
+### Note
+Not build-verified (no iOS runtime here). Self-reviewed: balanced braces/
+parens confirmed per-file. Structurally, the action row (with the Finish
+button) is only ever rendered when `isDoneToday`/`isMissedToday` are both
+false, so a watch-logged day already hides Finish entirely rather than
+needing a runtime guard against double-logging — the real gap was the
+CloudSync race above, not the button itself.

KisaniCal/Managers/CloudSyncManager.swift

@@ -84,7 +84,17 @@ final class CloudSyncManager {
         else { return }
 
         for key in changedKeys {
-            if let val = kv.object(forKey: key) {
+            guard let val = kv.object(forKey: key) else { continue }
+            if key.hasPrefix("kisani.workout.completedDates."), let incoming = val as? [String] {
+                // Workout dates are an append-only lifetime tally, and the Watch/
+                // HealthKit sync writes here independently of this device — a
+                // blind overwrite can race a fresh local write with a stale
+                // iCloud snapshot and silently drop already-logged days. Union
+                // instead, so an external change can only ever add days, never
+                // erase ones this device already knows about.
+                let existing = Set(UserDefaults.kisani.stringArray(forKey: key) ?? [])
+                UserDefaults.kisani.set(Array(existing.union(incoming)), forKey: key)
+            } else {
                 UserDefaults.kisani.set(val, forKey: key)
             }
         }

KisaniCal/Models/ExerciseModels.swift

@@ -663,20 +663,6 @@ class WorkoutViewModel: ObservableObject {
         save()
     }
 
-    /// Undo a "done" mark for a specific day — back to pending. Does NOT mark it
-    /// missed (that's a separate, explicit choice). Logged set data is kept.
-    func unmarkWorkoutDone(on date: Date) {
-        let key = iso.string(from: date)
-        workoutDates.removeAll { $0 == key }
-        save()
-    }
-
-    /// Undo a "missed" mark — back to pending, without claiming it was done.
-    func unmarkWorkoutMissed(on date: Date) {
-        let key = iso.string(from: date)
-        missedDates.removeAll { $0 == key }
-        save()
-    }
 
     // MARK: - Compensation (recover a missed workout on a rest day)
 

KisaniCal/Views/WorkoutView.swift

@@ -146,13 +146,7 @@ struct WorkoutView: View {
                     onFinish: { withAnimation(KisaniSpring.snappy) { vm.markWorkoutDone(on: Date()) } },
                     onMarkAllSets: { withAnimation(KisaniSpring.snappy) { vm.setAllSetsDone(true) } },
                     onClearAllSets: { withAnimation(KisaniSpring.snappy) { vm.setAllSetsDone(false) } },
-                    onNotCompleted: { withAnimation(KisaniSpring.snappy) { vm.markWorkoutMissed(on: Date()) } },
+                    onNotCompleted: { withAnimation(KisaniSpring.snappy) { vm.markWorkoutMissed(on: Date()) } }
-                    onUndo: {
-                        withAnimation(KisaniSpring.snappy) {
-                            if vm.isWorkoutMissed(on: Date()) { vm.unmarkWorkoutMissed(on: Date()) }
-                            else { vm.unmarkWorkoutDone(on: Date()) }
-                        }
-                    }
                 )
                     .listRowBackground(Color.clear)
                     .listRowSeparator(.hidden)
@@ -604,7 +598,6 @@ struct DotProgressCard: View {
     let onMarkAllSets: () -> Void
     let onClearAllSets: () -> Void
     let onNotCompleted: () -> Void
-    let onUndo: () -> Void
 
     /// Every quick action that changes today's state is confirmed first — a
     /// stray tap here shouldn't silently rewrite the day.
@@ -648,9 +641,10 @@ struct DotProgressCard: View {
                 DotGridProgress(progress: total > 0 ? progress : 0, cs: cs)
             }
 
-            if isDoneToday || isMissedToday {
+            // Watch/Health is the source of truth once today is logged — no
-                undoRow
+            // in-card way to undo that from here; the set checklist above is
-            } else {
+            // only for confirming sets, not for contesting the logged day.
+            if !(isDoneToday || isMissedToday) {
                 actionRow
             }
         }
@@ -740,7 +734,7 @@ struct DotProgressCard: View {
     private var actionRow: some View {
         VStack(spacing: 8) {
             Button {
-                if done == total && total > 0 { onFinish() } else { pendingAction = .finish }
+                pendingAction = .finish
             } label: {
                 Label(done == total && total > 0 ? "Finish Workout" : "Finish Anyway",
                       systemImage: "checkmark.circle.fill")
@@ -789,16 +783,6 @@ struct DotProgressCard: View {
         }
     }
 
-    private var undoRow: some View {
-        HStack {
-            Spacer()
-            Button(action: onUndo) {
-                Label("Undo", systemImage: "arrow.uturn.backward")
-                    .font(AppFonts.sans(11, weight: .semibold))
-            }
-            .foregroundColor(AppColors.accent)
-        }
-    }
 }
 
 // MARK: - Workout Stats