Guard every persisted read of retained workout models with isLive

A remotely deleted @Model traps on any persisted-property read, including
the observed expression of .onChange, which SwiftUI evaluates on every
body pass. Guard those expressions, the onAppear takeover read, and the
summary sheet's document mapping.

Claude-Session: https://claude.ai/code/session_01PKptrgbx74peTwHGRxBojv

Workouts/Views/WorkoutLogs/ExerciseView.swift

@@ -71,24 +71,30 @@ struct ExerciseView: View {
         }
         .onAppear {
             refreshDocIfNeeded()
-            // Take over this run: the watch parks and locks it while we're editing here.
-            services.watchBridge.setEditingWorkout(workout.id)
+            // Take over this run: the watch parks and locks it while we're editing
+            // here. Guarded — even `id` is a persisted property and traps when read
+            // on an entity a remote delete has already reaped.
+            if workout.isLive {
+                services.watchBridge.setEditingWorkout(workout.id)
+            }
         }
         .onDisappear {
             services.watchBridge.setEditingWorkout(nil)
         }
         // Reflect external changes (e.g. a set completed on the watch) live. Each edit
         // rewrites the whole workout file, so the cache always holds the latest — pulling
-        // it in can't revert a newer local tap.
-        .onChange(of: workout.updatedAt) { _, _ in
+        // it in can't revert a newer local tap. The observed expression is evaluated on
+        // every body pass, so it must be liveness-guarded like any persisted read.
+        .onChange(of: workout.isLive ? workout.updatedAt : nil) { _, _ in
             absorbExternalUpdate()
         }
     }
 
     /// Pull an externally-changed workout into the working copy so the plan and notes
-    /// update without leaving and re-entering the screen.
+    /// update without leaving and re-entering the screen. Skipped if the entity died
+    /// (remote delete) — mapping a dead @Model traps.
     private func absorbExternalUpdate() {
-        doc = WorkoutDocument(from: workout)
+        if let fresh = WorkoutDocument(fromLive: workout) { doc = fresh }
     }
 
     @ViewBuilder