[Bug]: VPN connection resets when starting containers on macOS 26.x with Cisco AnyConnect

### I have done the following

- [x] I have searched the existing issues
- [ ] If possible, I've reproduced the issue using the 'main' branch of this project

### Steps to reproduce

1. Install Cisco AnyConnect VPN (per machine).
2. Connect to VPN.
3. Start a container using the container CLI (tested with multiple subnets, including 172.31.250.1/24).
4. Observe that the VPN connection resets or disconnects as soon as the container starts.

### Current behavior

When starting any container, the Cisco AnyConnect VPN connection is immediately reset or disconnects. This happens regardless of the subnet chosen for the container network (tested with default and custom subnets). The issue appears on both macOS 26.0 and 26.0.1, with container versions 0.1.0 and 0.5.0.

### Expected behavior

Starting a container should not reset or disconnect the active VPN connection. VPN tunnel should remain stable while containers are started/stopped.

### Environment

```markdown
- OS: macOS 26.0.1 (25A354)
- VPN: Cisco AnyConnect, per machine install
- Container: 0.5.0 CLI
```

### Relevant log output

```shell
N/A (VPN reset is visible in AnyConnect UI; can provide syslog or diagnostic script output if needed)
```

### Code of Conduct

- [x] I agree to follow this project's Code of Conduct