[All Platforms][CLI&UX] OpenShell TUI selects wrong sandbox or hides pending network requests

## Description

When launching `openshell tui` targeting a non-default sandbox, the TUI shows "Sandbox: my-assistant" instead of the target sandbox (observed on dgxspark). On macOS, the TUI shows the correct sandbox but pending network requests are not visible in the approval panel.

## Environment

```text
Device: DGX Spark, macOS (Apple Silicon)
OS: Linux / macOS
Architecture: aarch64 / arm64
Node.js: v22.23.1
npm: 10.9.8
Docker: 29.x / 28.x
OpenShell CLI: openshell 0.0.85
NemoClaw: nemoclaw v0.0.89
OpenClaw: unknown
```

## Steps to Reproduce

1. Install NemoClaw v0.0.89, onboard default my-assistant
2. Create a second sandbox: `nemoclaw onboard --sandbox t57-test`
3. Launch TUI: `openshell tui`
4. Observe TUI header

## Expected Result

TUI should display the sandbox that was connected/targeted, and pending network requests should appear in the approval panel.

## Actual Result

- dgxspark: TUI shows "Sandbox: my-assistant" instead of test sandbox
- macOS: TUI shows correct sandbox but `example.com:80 (curl) [pending]` never appears

---
[NVB#6486169](https://nvbugspro.nvidia.com/bug/6486169)

Start by reproducing the issue with `nemoclaw onboard --sandbox t57-test` followed by `openshell tui` on Linux and macOS. Trace how the TUI determines the connected sandbox and populates the network approval panel. Done means the targeted sandbox is shown and pending requests such as `example.com:80 (curl)` appear on both platforms.

Written by the indexing model from the issue text.