refactor(browser_tests): remove deprecated proxy methods from ComfyPage

Migrate all test callers to use helper classes directly:

- nodeOps: getGraphNodesCount, getNodeRefById, selectNodes, etc.

- canvasOps: dragAndDrop, zoom, pan, resetView, etc.

- subgraph: rightClickInputSlot, connectToOutput, etc.

Reduces ComfyPage.ts from 1335 to 1085 lines (-250 lines).

Amp-Thread-ID: https://ampcode.com/threads/T-019c1318-58b7-757f-801c-5b676f0d3421
Co-authored-by: Amp <amp@ampcode.com>

browser_tests/tests/vueNodes/interactions/node/move.spec.ts

@@ -35,7 +35,7 @@ test.describe('Vue Node Moving', () => {
     async ({ comfyPage }) => {
       const loadCheckpointHeaderPos =
         await getLoadCheckpointHeaderPos(comfyPage)
-      await comfyPage.dragAndDrop(loadCheckpointHeaderPos, {
+      await comfyPage.canvasOps.dragAndDrop(loadCheckpointHeaderPos, {
         x: 256,
         y: 256
       })
@@ -56,7 +56,7 @@ test.describe('Vue Node Moving', () => {
 
       const loadCheckpointHeaderPos =
         await getLoadCheckpointHeaderPos(comfyPage)
-      await comfyPage.panWithTouch(
+      await comfyPage.canvasOps.panWithTouch(
         {
           x: 64,
           y: 64