Description

When using sessions_spawn with runtime: "acp", the ACP session output is delivered to the parent session's channel (Telegram in this case) regardless of acp.delivery.mode setting.

Steps to Reproduce

1. Configure OpenClaw with Telegram channel and agents.defaults.delivery.mode: "announce"
2. Set acp.delivery.mode: "none" to disable ACP delivery
3. Spawn an ACP session from main session:

   {
     "runtime": "acp",
     "agentId": "claude",
     "task": "Say hello"
   }

4. Observe: ACP session output appears in Telegram

Expected Behavior

With acp.delivery.mode: "none", ACP session output should NOT be delivered to any channel.

Actual Behavior

ACP sessions inherit the parent session's delivery context and send output to Telegram.

Workaround

Run acpx directly via exec instead of using sessions_spawn:

/usr/lib/node_modules/openclaw/extensions/acpx/node_modules/.bin/acpx \
  --cwd /workspace \
  --approve-all claude exec "prompt"

Environment

• OpenClaw: 2026.3.2
• Channel: Telegram
• ACP backend: acpx