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/features/background-agent/manager.ts

@@ -236,17 +236,10 @@ export class BackgroundManager {
     const parentDirectory = parentSession?.data?.directory ?? this.directory
     log(`[background-agent] Parent dir: ${parentSession?.data?.directory}, using: ${parentDirectory}`)
 
-    const inheritedPermission = (parentSession as any)?.data?.permission
-    const permissionRules = Array.isArray(inheritedPermission)
-      ? inheritedPermission.filter((r: any) => r?.permission !== "question")
-      : []
-    permissionRules.push({ permission: "question", action: "deny" as const, pattern: "*" })
-
     const createResult = await this.client.session.create({
       body: {
         parentID: input.parentSessionID,
         title: `${input.description} (@${input.agent} subagent)`,
-        permission: permissionRules,
       } as any,
       query: {
         directory: parentDirectory,