Suspend watch edit locks on background; degrade oversized pushes

Two watch-stranding fixes (BULLETPROOFING.md M1, M4):

The exclusive-edit lock rode in the latest-wins context and was cleared
only by onDisappear, so an editor left open in a pocketed (or
force-quit) phone parked the watch's run indefinitely ("Editing on
iPhone..."). The scene-phase hook now publishes the locks as cleared
while the app is backgrounded - without forgetting them locally - and
re-asserts them on return to the foreground.

pushAll treated a failed updateApplicationContext as log-only, so a
payload past WatchConnectivity's size ceiling silently froze the watch
out of all future state. A failed push now retries with the
recently-completed tail dropped (display-only on the watch); only a
failure of the slim push too remains an error.

Claude-Session: https://claude.ai/code/session_01PVNBVKp5bcq52X722uMjwT

Workouts/Connectivity/PhoneConnectivityBridge.swift

@@ -26,6 +26,13 @@ final class PhoneConnectivityBridge: NSObject {
     private(set) var editingWorkoutID: String?
     private(set) var editingSplitID: String?
 
+    /// While true (scene backgrounded), the edit locks are *published* to the watch as
+    /// cleared without being forgotten locally. An editor left open in a pocketed — or
+    /// force-quit — phone never fires `onDisappear`, and a lock that outlives its editor
+    /// parks the watch's run indefinitely ("Editing on iPhone…"). Restored on re-activate,
+    /// so returning to the still-open editor re-asserts the lock.
+    private var locksSuspended = false
+
     /// Monotonic sequence stamped on each live-run frame we send. Bumped to stay ahead of
     /// any frame we *receive*, so the two devices share one increasing sequence per run and
     /// either side can drop a stale / out-of-order delivery (see `LiveProgress.version`).
@@ -100,27 +107,47 @@ final class PhoneConnectivityBridge: NSObject {
         let restSeconds = UserDefaults.standard.object(forKey: WCPayload.restSecondsKey) as? Int ?? 45
         let doneCountdownSeconds = UserDefaults.standard.object(forKey: WCPayload.doneCountdownSecondsKey) as? Int ?? 5
         let weightUnit = UserDefaults.standard.string(forKey: WCPayload.weightUnitKey) ?? WeightUnit.lb.rawValue
-        let payload = WCPayload.encodeState(
-            splits: splits.map(SplitDocument.init(from:)),
-            workouts: workouts.map(WorkoutDocument.init(from:)),
-            restSeconds: restSeconds,
-            doneCountdownSeconds: doneCountdownSeconds,
-            weightUnit: weightUnit,
-            editingWorkoutID: editingWorkoutID,
-            editingSplitID: editingSplitID
-        )
+        let splitDocs = splits.map(SplitDocument.init(from:))
+        func encode(_ included: [Workout]) -> [String: Any] {
+            WCPayload.encodeState(
+                splits: splitDocs,
+                workouts: included.map(WorkoutDocument.init(from:)),
+                restSeconds: restSeconds,
+                doneCountdownSeconds: doneCountdownSeconds,
+                weightUnit: weightUnit,
+                editingWorkoutID: locksSuspended ? nil : editingWorkoutID,
+                editingSplitID: locksSuspended ? nil : editingSplitID
+            )
+        }
         do {
+            let payload = encode(workouts)
             try session.updateApplicationContext(payload)
             let bytes = ((payload[WCPayload.splitsKey] as? Data)?.count ?? 0)
                 + ((payload[WCPayload.workoutsKey] as? Data)?.count ?? 0)
             Self.log.info("pushAll: \(splits.count) splits, \(workouts.count) workouts (\(bytes) bytes)")
         } catch {
-            // Payload-too-large / not-activated etc. — must be visible, or the watch
-            // just silently never hears about this state.
-            Self.log.error("updateApplicationContext failed: \(error, privacy: .public)")
+            // Realistically payload-too-large. The context is the watch's lifeline — a
+            // dropped push means it silently never hears about this state again — so
+            // degrade rather than freeze: the recently-completed tail is display-only
+            // on the watch, drop it and retry with just the active runs.
+            do {
+                try session.updateApplicationContext(encode(active))
+                Self.log.warning("pushAll degraded to \(active.count) active workouts (dropped \(recentCompleted.count) completed): \(error, privacy: .public)")
+            } catch {
+                Self.log.error("updateApplicationContext failed: \(error, privacy: .public)")
+            }
         }
     }
 
+    /// Scene-phase hook: suspend the published edit locks while the app is backgrounded,
+    /// restore them when it returns to the foreground (see `locksSuspended`). Pushes only
+    /// when a lock is actually set — otherwise the flip changes nothing on the wire.
+    func setLocksSuspended(_ suspended: Bool) {
+        guard locksSuspended != suspended else { return }
+        locksSuspended = suspended
+        if editingWorkoutID != nil || editingSplitID != nil { pushAll() }
+    }
+
     /// Mark (or clear, with `nil`) the workout currently open in a phone exercise editor.
     /// The watch parks that run and blocks re-entry until it clears. Pushes immediately so
     /// the lock takes effect without waiting on a cache change.