test: migrate as unknown as to @total-typescript/shoehorn (#10761)

*PR Created by the Glary-Bot Agent*

---

## Summary

- Replace all `as unknown as Type` assertions in 59 unit test files with
type-safe `@total-typescript/shoehorn` functions
- Use `fromPartial<Type>()` for partial mock objects where deep-partial
type-checks (21 files)
- Use `fromAny<Type>()` for fundamentally incompatible types: null,
undefined, primitives, variables, class expressions, and mocks with
test-specific extra properties that `PartialDeepObject` rejects
(remaining files)
- All explicit type parameters preserved so TypeScript return types are
correct
- Browser test `.spec.ts` files excluded (shoehorn unavailable in
`page.evaluate` browser context)

## Verification

- `pnpm typecheck` ✅
- `pnpm lint` ✅
- `pnpm format` ✅
- Pre-commit hooks passed (format + oxlint + eslint + typecheck)
- Migrated test files verified passing (ran representative subset)
- No test behavior changes — only type assertion syntax changed
- No UI changes — screenshots not applicable

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-10761-test-migrate-as-unknown-as-to-total-typescript-shoehorn-3336d73d365081f6b8adc44db5dcc380)
by [Unito](https://www.unito.io)

---------

Co-authored-by: Glary-Bot <glary-bot@users.noreply.github.com>
Co-authored-by: Amp <amp@ampcode.com>

src/core/graph/subgraph/resolveSubgraphInputLink.test.ts

@@ -1,4 +1,5 @@
 import { createTestingPinia } from '@pinia/testing'
+import { fromPartial } from '@total-typescript/shoehorn'
 import { setActivePinia } from 'pinia'
 import { beforeEach, describe, expect, test, vi } from 'vitest'
 
@@ -101,14 +102,14 @@ describe('resolveSubgraphInputLink', () => {
     vi.spyOn(subgraph, 'getLink').mockImplementation((linkId) => {
       if (typeof linkId !== 'number') return originalGetLink(linkId)
       if (linkId === stale.linkId) {
-        return {
+        return fromPartial<ReturnType<typeof subgraph.getLink>>({
           resolve: () => ({
             inputNode: {
               inputs: undefined,
               getWidgetFromSlot: () => ({ name: 'ignored' })
             }
           })
-        } as unknown as ReturnType<typeof subgraph.getLink>
+        })
       }
 
       return originalGetLink(linkId)