Contextmenu Monkeypatch Standardization (#5977)

This pull request introduces a new extension API for context menu
customization, allowing extensions to contribute items to both canvas
and node right-click menus. It adds two collection methods to the
`ComfyApp` class to aggregate these menu items from all registered
extensions, and updates the extension interface accordingly.
Comprehensive unit tests are included to verify the correct aggregation
behavior and error handling.

**Extension API for Context Menus:**

* Added optional `getCanvasMenuItems` and `getNodeMenuItems` methods to
the `ComfyExtension` interface, enabling extensions to provide context
menu items for canvas and node right-click menus (`src/types/comfy.ts`).

* Updated type imports to support the new API, including
`IContextMenuValue`, `LGraphCanvas`, and `LGraphNode`
(`src/types/comfy.ts`, `src/scripts/app.ts`).
[[1]](diffhunk://#diff-c29886a1b0c982c6fff3545af0ca8ec269876c2cf3948f867d08c14032c04d66L1-R5)
[[2]](diffhunk://#diff-bde0dce9fe2403685d27b0e94a938c3d72824d02d01d1fd6167a0dddc6e585ddR10)

**Core Implementation:**

* Implemented `collectCanvasMenuItems` and `collectNodeMenuItems`
methods in the `ComfyApp` class to gather menu items from all
extensions, with robust error handling and logging for extension
failures (`src/scripts/app.ts`).

**Testing:**

* Added a comprehensive test suite for the new context menu extension
API, covering aggregation logic, error handling, and integration
scenarios (`tests-ui/tests/extensions/contextMenuExtension.test.ts`).

This is PR 1 of the 3 PRs in the Contextmenu standardizations.
-https://github.com/Comfy-Org/ComfyUI_frontend/pull/5992
-https://github.com/Comfy-Org/ComfyUI_frontend/pull/5993

src/scripts/app.ts

@@ -7,6 +7,7 @@ import { shallowRef } from 'vue'
 import { useCanvasPositionConversion } from '@/composables/element/useCanvasPositionConversion'
 import { registerProxyWidgets } from '@/core/graph/subgraph/proxyWidget'
 import { st, t } from '@/i18n'
+import type { IContextMenuValue } from '@/lib/litegraph/src/interfaces'
 import {
   LGraph,
   LGraphCanvas,
@@ -1667,6 +1668,28 @@ export class ComfyApp {
     useExtensionService().registerExtension(extension)
   }
 
+  /**
+   * Collects context menu items from all extensions for canvas menus
+   * @param canvas The canvas instance
+   * @returns Array of context menu items from all extensions
+   */
+  collectCanvasMenuItems(canvas: LGraphCanvas): IContextMenuValue[] {
+    return useExtensionService()
+      .invokeExtensions('getCanvasMenuItems', canvas)
+      .flat() as IContextMenuValue[]
+  }
+
+  /**
+   * Collects context menu items from all extensions for node menus
+   * @param node The node being right-clicked
+   * @returns Array of context menu items from all extensions
+   */
+  collectNodeMenuItems(node: LGraphNode): IContextMenuValue[] {
+    return useExtensionService()
+      .invokeExtensions('getNodeMenuItems', node)
+      .flat() as IContextMenuValue[]
+  }
+
   /**
    * Refresh combo list on whole nodes
    */