[backport core/1.42] fix: make graph canvas toolbar visible on mobile (#10274)

Backport of #10168 to `core/1.42`

Automatically created by backport workflow.

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-10274-backport-core-1-42-fix-make-graph-canvas-toolbar-visible-on-mobile-3276d73d3650811fbea5dce7bcce299e)
by [Unito](https://www.unito.io)

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

src/components/LiteGraphCanvasSplitterOverlay.test.ts

@@ -0,0 +1,28 @@
+import { readFileSync } from 'fs'
+import { resolve } from 'path'
+import { describe, expect, it } from 'vitest'
+
+/**
+ * Regression test: the graph-canvas-panel SplitterPanel must not clip
+ * absolutely-positioned children (like GraphCanvasMenu).
+ *
+ * PrimeVue applies `overflow: hidden` to all SplitterPanels by default.
+ * Without an explicit `overflow-visible` override, the bottom-right canvas
+ * toolbar becomes invisible on mobile viewports where the panel's bounding
+ * box is smaller than the full canvas area.
+ *
+ * @see https://www.notion.so/Bug-Graph-canvas-toolbar-not-visible-on-mobile-3246d73d36508144ae00f10065c42fac
+ */
+describe('LiteGraphCanvasSplitterOverlay', () => {
+  it('graph-canvas-panel has overflow-visible to prevent clipping toolbar on mobile', () => {
+    const filePath = resolve(__dirname, 'LiteGraphCanvasSplitterOverlay.vue')
+    const source = readFileSync(filePath, 'utf-8')
+
+    // The SplitterPanel wrapping graph-canvas-panel must include overflow-visible
+    // to override PrimeVue's default overflow:hidden on .p-splitterpanel.
+    // Without this, GraphCanvasMenu (absolute right-0 bottom-0) gets clipped on mobile.
+    expect(source).toMatch(
+      /class="[^"]*graph-canvas-panel[^"]*overflow-visible/
+    )
+  })
+})