bug: sandbox create progress repeats 'Sandbox allocated' during image pull #2674

Agent Diagnostic

• Skills loaded: create-github-issue, openshell-cli
• OpenShell version tested: 0.0.101
• Latest release checked: unable to verify (testing against dev build)
• Known fixes reviewed: unable to verify
• Possible duplicates reviewed: searched "sandbox allocated progress repeat" and "sandbox create progress display", no results
• Findings: The CLI's sandbox create progress renderer emits a new line for every gRPC status poll response instead of updating in-place. During image pull (which can take 30-60s), the status stays at "Sandbox allocated" while the container runtime pulls the image, producing dozens to hundreds of identical lines.
• Remaining reason for filing: The output floods the terminal and obscures the actual progress information.

Description

Actual behavior: When creating a sandbox with a large or uncached container image, openshell sandbox create prints "Sandbox allocated (0s)" on a new line for every status poll iteration while the image is being pulled. This produces 30-100+ identical lines depending on pull duration:

✓ Sandbox allocated (0s)
✓ Sandbox allocated (0s)
✓ Sandbox allocated (0s)
✓ Sandbox allocated (0s)
... (repeats dozens of times)
✓ Image already present
✓ Starting sandbox

Expected behavior: The progress display should either:

1. Update the current line in-place (overwrite with \r or terminal cursor control) when the status hasn't changed, or
2. Deduplicate consecutive identical status messages and only print when the phase or message text changes, or
3. Show a spinner/progress indicator for long-running phases like image pull

Reproduction Steps

1. Create a sandbox using an image that isn't cached in the container runtime:

   openshell sandbox create --name test \
     --from <large-uncached-image>:latest \
     --no-tty -- sh -c "echo ready"

2. Observe the terminal output during image pull

The issue is most visible with the Docker compute driver inside SAW VMs where image pulls go through the internal OpenShift registry. Images cached locally produce only 1-2 lines (no delay between allocation and start).

Environment

• OS: macOS (client), Fedora 44 (VM/sandbox host)
• Compute driver: Docker (inside SAW VM on OpenShift Virtualization)
• OpenShell CLI: 0.0.101
• Gateway: 0.0.102-dev.4
• Latest release checked: no
• Possible duplicates checked: yes, none found