fix: improve link visibility toggle test stability

Replace fixed delays with frame counter monitoring to ensure canvas
has completed rendering before taking screenshots. This eliminates
race conditions and makes the test more reliable.

🤖 Generated with [Claude Code](https://claude.ai/code)

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

browser_tests/tests/graphCanvasMenu.spec.ts

@@ -37,11 +37,21 @@ test.describe('Graph Canvas Menu', () => {
       { timeout: 5000 }
     )
 
-    // Wait for canvas to complete rendering with hidden links
-    // Use multiple frames and a small delay to ensure canvas is fully updated
-    await comfyPage.nextFrame()
-    await comfyPage.nextFrame()
-    await comfyPage.page.waitForTimeout(100) // Small delay for canvas rendering
+    // Wait for canvas to complete rendering by monitoring the frame counter
+    // The canvas increments its frame counter after each draw cycle
+    const frameBeforeRender = await comfyPage.page.evaluate(() => {
+      return window['app']?.canvas?.frame || 0
+    })
+
+    await comfyPage.page.waitForFunction(
+      (initialFrame) => {
+        const canvas = window['app']?.canvas
+        // Wait for at least one frame to be rendered after the change
+        return canvas && canvas.frame > initialFrame
+      },
+      frameBeforeRender,
+      { timeout: 5000 }
+    )
 
     await expect(comfyPage.canvas).toHaveScreenshot(
       'canvas-with-hidden-links.png'
@@ -68,11 +78,20 @@ test.describe('Graph Canvas Menu', () => {
       { timeout: 5000 }
     )
 
-    // Wait for canvas to complete rendering with visible links
-    // Use multiple frames and a small delay to ensure canvas is fully updated
-    await comfyPage.nextFrame()
-    await comfyPage.nextFrame()
-    await comfyPage.page.waitForTimeout(100) // Small delay for canvas rendering
+    // Wait for canvas to complete rendering by monitoring the frame counter
+    const frameBeforeSecondRender = await comfyPage.page.evaluate(() => {
+      return window['app']?.canvas?.frame || 0
+    })
+
+    await comfyPage.page.waitForFunction(
+      (initialFrame) => {
+        const canvas = window['app']?.canvas
+        // Wait for at least one frame to be rendered after the change
+        return canvas && canvas.frame > initialFrame
+      },
+      frameBeforeSecondRender,
+      { timeout: 5000 }
+    )
 
     await expect(comfyPage.canvas).toHaveScreenshot(
       'canvas-with-visible-links.png'