fix(subagent): remove permission.question=deny override that caused zombie sessions

Child session creation was injecting permission: { question: 'deny' } which
conflicted with OpenCode's child session permission handling, causing subagent
sessions to hang with 0 messages after creation (zombie state).

Remove the permission override from all session creators (BackgroundManager,
sync-session-creator, call-omo-agent) and rely on prompt-level tool restrictions
(tools.question=false) to maintain the intended policy.

Closes #1711

src/tools/delegate-task/sync-session-creator.ts

@@ -13,9 +13,6 @@ export async function createSyncSession(
     body: {
       parentID: input.parentSessionID,
       title: `${input.description} (@${input.agentToUse} subagent)`,
-      permission: [
-        { permission: "question", action: "deny" as const, pattern: "*" },
-      ],
     } as any,
     query: {
       directory: parentDirectory,