perf: remove deep: true from 3 hot watchers to reduce reactivity overhead (#9248)

All three watchers used { deep: true } unnecessarily because their
watched sources already produce new object/array references on change,
making deep traversal redundant:

- GraphView.vue: queueStore.tasks is a computed that spreads three
  shallowRef arrays into a new array each time. TaskItemImpl instances
  are immutable (readonly fields, replaced not mutated).

- DomWidget.vue: Replaced opaque widgetState deep watcher with explicit
  property deps (pos, size, zIndex, readonly, positionOverride). During
  60 FPS pan/zoom, Vue no longer walks the entire DomWidgetState object
  graph including the markRaw widget — only 5 leaf properties are
  checked. pos and size are new array literals each frame; the rest are
  primitives.

- GraphCanvas.vue: nodeLocationProgressStates is a computed returning a
  new Record on every execution progress event (nodeProgressStates is
  replaced wholesale via WebSocket handler).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-9248-perf-remove-deep-true-from-3-hot-watchers-to-reduce-reactivity-overhead-3136d73d365081278f18da5a2eef6971)
by [Unito](https://www.unito.io)

Co-authored-by: bymyself <cbyrne@comfy.org>

src/components/graph/GraphCanvas.vue

@@ -363,7 +363,14 @@ watch(
   }
 )
 
-// Update the progress of executing nodes
+/**
+ * Propagates execution progress from the store to LiteGraph node objects
+ * and triggers a canvas redraw.
+ *
+ * No `deep: true` needed — `nodeLocationProgressStates` is a computed that
+ * returns a new `Record` object on every progress event (the underlying
+ * `nodeProgressStates` ref is replaced wholesale by the WebSocket handler).
+ */
 watch(
   () =>
     [executionStore.nodeLocationProgressStates, canvasStore.canvas] as const,
@@ -381,8 +388,7 @@ watch(
 
     // Force canvas redraw to ensure progress updates are visible
     canvas.setDirty(true, false)
-  },
-  { deep: true }
+  }
 )
 
 // Update node slot errors for LiteGraph nodes

src/views/GraphView.vue

@@ -142,11 +142,18 @@ watch(
   { immediate: true }
 )
 
+/**
+ * Reports task completion telemetry to Electron analytics when tasks
+ * transition from running to history.
+ *
+ * No `deep: true` needed — `queueStore.tasks` is a computed that spreads
+ * three `shallowRef` arrays into a new array on every change, and
+ * `TaskItemImpl` instances are immutable (replaced, never mutated).
+ */
 if (isDesktop) {
   watch(
     () => queueStore.tasks,
     (newTasks, oldTasks) => {
-      // Report tasks that previously running but are now completed (i.e. in history)
       const oldRunningTaskIds = new Set(
         oldTasks.filter((task) => task.isRunning).map((task) => task.jobId)
       )
@@ -161,8 +168,7 @@ if (isDesktop) {
             status: task.displayStatus.toLowerCase()
           })
         })
-    },
-    { deep: true }
+    }
   )
 }