feat(subagent): block question tool at both SDK and hook level

- Add permission: [{ permission: 'question', action: 'deny' }] to session.create()
  in background-agent and delegate-task for SDK-level blocking
- Add subagent-question-blocker hook as backup layer to intercept question tool
  calls in tool.execute.before event
- Ensures subagents cannot ask questions to users and must work autonomously

src/tools/delegate-task/tools.ts

@@ -864,7 +864,10 @@ To continue this session: session_id="${task.sessionID}"`
           body: {
             parentID: ctx.sessionID,
             title: `Task: ${args.description}`,
-          },
+            permission: [
+              { permission: "question", action: "deny" as const, pattern: "*" },
+            ],
+          } as any,
           query: {
             directory: parentDirectory,
           },