refactor: address review feedback on Input device PR

- Clean up onDetectedDeviceChange callback when canvas is replaced
- Migrate legacy NavigationMode/MouseWheelScroll on first run
- Drop unreachable !isTrackpad branch in trackpad pan path
- Rename isStandardNavMode to isTrackpadWheelMode for clarity

src/lib/litegraph/src/LGraphCanvas.ts

@@ -3929,15 +3929,10 @@ export class LGraphCanvas implements CustomEventDispatcher<LGraphCanvasEventMap>
         this.ds.changeScale(scale, [e.clientX, e.clientY])
       }
     } else {
-      // Trackpads and mice work on significantly different scales
-      const factor = isTrackpad ? 0.18 : 0.008_333
-
-      if (!isTrackpad && e.shiftKey && e.deltaX === 0) {
-        this.ds.offset[0] -= e.deltaY * (1 + factor) * (1 / scale)
-      } else {
-        this.ds.offset[0] -= e.deltaX * (1 + factor) * (1 / scale)
-        this.ds.offset[1] -= e.deltaY * (1 + factor) * (1 / scale)
-      }
+      // Trackpad two-finger pan: outer condition guarantees isTrackpad here
+      const factor = 0.18
+      this.ds.offset[0] -= e.deltaX * (1 + factor) * (1 / scale)
+      this.ds.offset[1] -= e.deltaY * (1 + factor) * (1 / scale)
     }
 
     this.graph.change()

src/platform/settings/composables/useLitegraphSettings.ts

@@ -10,6 +10,34 @@ import { useSettingStore } from '@/platform/settings/settingStore'
 // eslint-disable-next-line import-x/no-restricted-paths
 import { useCanvasStore } from '@/renderer/core/canvas/canvasStore'
 
+/**
+ * One-time translation of the legacy `Comfy.Canvas.NavigationMode` +
+ * `Comfy.Canvas.MouseWheelScroll` pair into the new `Comfy.Graph.WheelInputMode`
+ * preference, preserving explicit choices made by users on previous versions.
+ *
+ * Idempotency is achieved by resetting NavigationMode to its default after
+ * migration: subsequent boots see `legacy` and exit early.
+ */
+async function migrateLegacyNavigationSettings(
+  settingStore: ReturnType<typeof useSettingStore>
+) {
+  const navMode = settingStore.get('Comfy.Canvas.NavigationMode')
+  if (navMode === 'legacy') return
+
+  let migrated: 'mouse' | 'trackpad' | undefined
+  if (navMode === 'standard') {
+    migrated = 'trackpad'
+  } else if (navMode === 'custom') {
+    const wheelScroll = settingStore.get('Comfy.Canvas.MouseWheelScroll')
+    migrated = wheelScroll === 'panning' ? 'trackpad' : 'mouse'
+  }
+
+  if (migrated && settingStore.get('Comfy.Graph.WheelInputMode') === 'auto') {
+    await settingStore.set('Comfy.Graph.WheelInputMode', migrated)
+  }
+  await settingStore.set('Comfy.Canvas.NavigationMode', 'legacy')
+}
+
 /**
  * Watch for changes in the setting store and update the LiteGraph settings accordingly.
  */
@@ -17,6 +45,8 @@ export const useLitegraphSettings = () => {
   const settingStore = useSettingStore()
   const canvasStore = useCanvasStore()
 
+  void migrateLegacyNavigationSettings(settingStore)
+
   watchEffect(() => {
     const canvasInfoEnabled = settingStore.get('Comfy.Graph.CanvasInfo')
     if (canvasStore.canvas) {
@@ -158,15 +188,21 @@ export const useLitegraphSettings = () => {
   /**
    * Mirror the canvas pointer's auto-detected device onto a reactive ref so
    * settings UI can show the current detection inside the "Auto" option.
+   * The cleanup detaches the handler from the previous pointer so a stale
+   * canvas instance can no longer mutate the shared ref after replacement.
    */
-  watchEffect(() => {
+  watchEffect((onCleanup) => {
     const { canvas } = canvasStore
     if (!canvas) return
+    const { pointer } = canvas
     const { detectedInputDevice } = useInputDeviceDetection()
-    detectedInputDevice.value = canvas.pointer.detectedDevice
-    canvas.pointer.onDetectedDeviceChange = (device) => {
+    detectedInputDevice.value = pointer.detectedDevice
+    pointer.onDetectedDeviceChange = (device) => {
       detectedInputDevice.value = device
     }
+    onCleanup(() => {
+      pointer.onDetectedDeviceChange = undefined
+    })
   })
 
   watchEffect(() => {

src/renderer/core/canvas/useCanvasInteractions.ts

@@ -14,7 +14,7 @@ export function useCanvasInteractions() {
   const canvasStore = useCanvasStore()
   const { getCanvas } = canvasStore
 
-  const isStandardNavMode = computed(
+  const isTrackpadWheelMode = computed(
     () => settingStore.get('Comfy.Graph.WheelInputMode') === 'trackpad'
   )
 
@@ -43,7 +43,7 @@ export function useCanvasInteractions() {
 
   const shouldForwardWheelEvent = (event: WheelEvent): boolean =>
     !wheelCapturedByFocusedElement(event) ||
-    (isStandardNavMode.value && (event.ctrlKey || event.metaKey))
+    (isTrackpadWheelMode.value && (event.ctrlKey || event.metaKey))
 
   /**
    * Handles wheel events from UI components that should be forwarded to canvas
@@ -53,13 +53,13 @@ export function useCanvasInteractions() {
     if (!shouldForwardWheelEvent(event)) return
 
     // In standard mode, Ctrl+wheel should go to canvas for zoom
-    if (isStandardNavMode.value && (event.ctrlKey || event.metaKey)) {
+    if (isTrackpadWheelMode.value && (event.ctrlKey || event.metaKey)) {
       forwardEventToCanvas(event)
       return
     }
 
     // In legacy mode, all wheel events go to canvas for zoom
-    if (!isStandardNavMode.value) {
+    if (!isTrackpadWheelMode.value) {
       forwardEventToCanvas(event)
       return
     }