test: strengthen malformed message guard coverage

src/hooks/task-session-manager/index.test.ts

@@ -44,7 +44,14 @@ function createMessages(sessionID: string, text = 'user message') {
 
 describe('task-session-manager hook', () => {
   test('ignores messages without OpenCode info or parts', async () => {
-    const { hook } = createHook();
+    const board = new BackgroundJobBoard();
+    board.registerLaunch({
+      taskID: 'child-1',
+      parentSessionID: 'parent-1',
+      agent: 'explorer',
+      description: 'map scheduler hooks',
+    });
+    const { hook } = createHook({ backgroundJobBoard: board });
     const messages = {
       messages: [
         {},
@@ -54,12 +61,22 @@ describe('task-session-manager hook', () => {
           info: { role: 'assistant' },
           parts: [{ type: 'text', text: 'assistant response' }],
         },
+        {
+          info: { role: 'user', agent: 'orchestrator', sessionID: 'parent-1' },
+          parts: [{ type: 'text', text: 'valid user message' }],
+        },
       ],
     };
 
     await hook['experimental.chat.messages.transform']({}, messages as never);
 
-    expect(messages.messages).toHaveLength(4);
+    expect(messages.messages).toHaveLength(5);
+    expect(messages.messages[4].parts[0].text).toContain(
+      '### Background Job Board',
+    );
+    expect(messages.messages[4].parts[0].text).toContain(
+      'exp-1 / child-1 / explorer / running',
+    );
   });
 
   test('stores background task launches in job board prompt context', async () => {