test(tools): remove unsafe test assertions

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

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

src/tools/hashline-edit/normalize-edits.test.ts

@@ -51,9 +51,9 @@ describe("normalizeHashlineEdits", () => {
 
   it("rejects legacy payload without op", () => {
     //#given
-    const input = [{ type: "set_line", line: "2#VK", text: "updated" }] as unknown as Parameters<
+    const input = testCoerce<Parameters<
       typeof normalizeHashlineEdits
-    >[0]
+    >[0]>([{ type: "set_line", line: "2#VK", text: "updated" }])
 
     //#when / #then
     expect(() => normalizeHashlineEdits(input)).toThrow(/legacy format was removed/i)

src/tools/hashline-edit/tools.test.ts

@@ -8,14 +8,14 @@ import * as os from "node:os"
 import * as path from "node:path"
 
 function createMockContext(): ToolContext {
-  return {
+  return testCoerce<ToolContext>({
     sessionID: "test",
     messageID: "test",
     agent: "test",
     abort: new AbortController().signal,
     metadata: mock(() => {}),
     ask: async () => {},
-  } as unknown as ToolContext
+  })
 }
 
 describe("createHashlineEditTool", () => {