test(hooks): remove unsafe test assertions

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

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

src/hooks/keyword-detector/index.test.ts

@@ -881,13 +881,13 @@ describe("keyword-detector team mode", () => {
   })
 
   function createMockPluginInput() {
-    return {
+    return testCoerce<PluginInput>({
       client: {
         tui: {
           showToast: async () => {},
         },
       },
-    } as unknown as PluginInput
+    })
   }
 
   test("should inject team-mode message when user types 'team mode'", async () => {
@@ -1063,7 +1063,7 @@ describe("keyword-detector disabled_keywords config", () => {
 
   function createMockPluginInput(options: { toastCalls?: string[] } = {}) {
     const toastCalls = options.toastCalls ?? []
-    return {
+    return testCoerce<PluginInput>({
       client: {
         tui: {
           showToast: async (opts: { body: { title: string } }) => {
@@ -1071,7 +1071,7 @@ describe("keyword-detector disabled_keywords config", () => {
           },
         },
       },
-    } as unknown as PluginInput
+    })
   }
 
   test("should NOT inject search-mode when disabled_keywords includes 'search'", async () => {