test: make unsafe test coercion explicit

Move test coercion out of a hidden global and require each test to import the helper so review tools and runtime scripts can see the unsafe boundary.

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/tools/delegate-task/category-resolver.test.ts

@@ -3,6 +3,7 @@ const { describe, test, expect, beforeEach, afterEach, spyOn, mock } = require("
 import { resolveCategoryExecution } from "./category-resolver"
 import type { ExecutorContext } from "./executor-types"
 import * as connectedProvidersCache from "../../shared/connected-providers-cache"
+import { unsafeTestValue } from "../../../test-support/unsafe-test-value"
 
 describe("resolveCategoryExecution", () => {
 	let connectedProvidersSpy: ReturnType<typeof spyOn> | undefined
@@ -26,8 +27,8 @@ describe("resolveCategoryExecution", () => {
 	})
 
 	const createMockExecutorContext = (): ExecutorContext => ({
-		client: testCoerce({}),
-		manager: testCoerce({}),
+		client: unsafeTestValue({}),
+		manager: unsafeTestValue({}),
 		directory: "/tmp/test",
 		userCategories: {},
 		sisyphusJuniorModel: undefined,