Chore: Typescript cleanup (1 / N) (#7817)

## Summary

Remove 178 `@ts-expect-error` suppressions (935 → 757, 19% reduction) by
fixing underlying type issues instead of suppressing errors.

## Changes

- **What**: Type safety improvements across `src/lib/litegraph/` and
related test files
  - Prefix unused callback parameters with `_` instead of suppressing
  - Use type intersections for mock methods on real objects
  - Use `Partial<T>` for incomplete test objects instead of `as unknown`
  - Add non-null assertions after `.toBeDefined()` checks in tests
  - Let TypeScript infer vitest fixture parameter types
- **Breaking**: None

## Review Focus

- `LGraphCanvas.ts` has the largest changes (232 lines) — all mechanical
unused parameter fixes
- Test files use type intersection pattern for mocks: `node as
LGraphNode & { mockFn: ... }`
- Removed dead code: `src/platform/cloud/onboarding/auth.ts` (47 lines,
unused)

### Key Files
| File | Change |
|------|--------|
| `LGraphCanvas.ts` | 57 suppressions removed (unused params) |
| `subgraph/__fixtures__/*` | Fixture type improvements |
| `*.test.ts` files | Mock typing with intersections |

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-7817-WIP-Chore-Typescript-cleanup-2da6d73d365081d1ade9e09a6c5bf935)
by [Unito](https://www.unito.io)

---------

Co-authored-by: Amp <amp@ampcode.com>
Co-authored-by: GitHub Action <action@github.com>

src/extensions/core/groupNode.ts

@@ -196,8 +196,7 @@ export class GroupNodeConfig {
   primitiveToWidget: {}
   nodeInputs: {}
   outputVisibility: any[]
-  // @ts-expect-error fixme ts strict error
-  nodeDef: ComfyNodeDef
+  nodeDef: (ComfyNodeDef & { [GROUP]: GroupNodeConfig }) | undefined
   // @ts-expect-error fixme ts strict error
   inputs: any[]
   // @ts-expect-error fixme ts strict error
@@ -231,8 +230,7 @@ export class GroupNodeConfig {
       output: [],
       output_name: [],
       output_is_list: [],
-      // @ts-expect-error Unused, doesn't exist
-      output_is_hidden: [],
+      output_node: false, // This is a lie (to satisfy the interface)
       name: source + SEPARATOR + this.name,
       display_name: this.name,
       category: 'group nodes' + (SEPARATOR + source),
@@ -261,6 +259,7 @@ export class GroupNodeConfig {
     }
     // @ts-expect-error fixme ts strict error
     this.#convertedToProcess = null
+    if (!this.nodeDef) return
     await app.registerNodeDef(`${PREFIX}${SEPARATOR}` + this.name, this.nodeDef)
     useNodeDefStore().addNodeDef(this.nodeDef)
   }

src/extensions/core/load3d/CameraManager.ts

@@ -13,8 +13,6 @@ export class CameraManager implements CameraManagerInterface {
   orthographicCamera: THREE.OrthographicCamera
   activeCamera: THREE.Camera
 
-  // @ts-expect-error unused variable
-  private renderer: THREE.WebGLRenderer
   private eventManager: EventManagerInterface
 
   private controls: OrbitControls | null = null
@@ -42,10 +40,9 @@ export class CameraManager implements CameraManagerInterface {
   }
 
   constructor(
-    renderer: THREE.WebGLRenderer,
+    _renderer: THREE.WebGLRenderer,
     eventManager: EventManagerInterface
   ) {
-    this.renderer = renderer
     this.eventManager = eventManager
 
     this.perspectiveCamera = new THREE.PerspectiveCamera(

src/extensions/core/load3d/SceneManager.ts

@@ -27,13 +27,11 @@ export class SceneManager implements SceneManagerInterface {
   private renderer: THREE.WebGLRenderer
 
   private getActiveCamera: () => THREE.Camera
-  // @ts-expect-error unused variable
-  private getControls: () => OrbitControls
 
   constructor(
     renderer: THREE.WebGLRenderer,
     getActiveCamera: () => THREE.Camera,
-    getControls: () => OrbitControls,
+    _getControls: () => OrbitControls,
     eventManager: EventManagerInterface
   ) {
     this.renderer = renderer
@@ -41,7 +39,6 @@ export class SceneManager implements SceneManagerInterface {
     this.scene = new THREE.Scene()
 
     this.getActiveCamera = getActiveCamera
-    this.getControls = getControls
 
     this.gridHelper = new THREE.GridHelper(20, 20)
     this.gridHelper.position.set(0, 0, 0)

src/extensions/core/load3d/ViewHelperManager.ts

@@ -14,16 +14,13 @@ export class ViewHelperManager implements ViewHelperManagerInterface {
   private getActiveCamera: () => THREE.Camera
   private getControls: () => OrbitControls
   private eventManager: EventManagerInterface
-  // @ts-expect-error unused variable
-  private renderer: THREE.WebGLRenderer
 
   constructor(
-    renderer: THREE.WebGLRenderer,
+    _renderer: THREE.WebGLRenderer,
     getActiveCamera: () => THREE.Camera,
     getControls: () => OrbitControls,
     eventManager: EventManagerInterface
   ) {
-    this.renderer = renderer
     this.getActiveCamera = getActiveCamera
     this.getControls = getControls
     this.eventManager = eventManager