Add sandbox prerequisites status bar item and install modal

[jasonsmithio]

Summary

Second half of the sandbox-prerequisites feature. PR #23 shipped the detection layer (data + CLI). This PR layers the in-editor UI on top: a status-bar indicator and an install-guidance modal.

PR-C (enforcement: tool gating + settings) is still to come and is intentionally scoped out here.

Architecture

New crate paddleboard_sandbox_prereqs_ui (~390 lines, one file). Three pieces hang together:

• SandboxPrereqs — a gpui::Global holding Option<SandboxStatus> plus a refreshing flag. The probe runs on tokio's pool via gpui_tokio::Tokio::spawn (necessary because the underlying check() uses tokio::process::Command), and the result is written back to the global with cx.update_global on the foreground thread. Views observe via cx.observe_global::<SandboxPrereqs> and re-render when the probe completes.

• SandboxStatusItem — implements workspace::StatusItemView. An IconButton with IconName::Box, colored by severity (Unknown / Ok / Warning / Error). Click dispatches paddleboard::OpenSandboxPrereqs. Tooltip is severity-specific ("Sandbox: gVisor not configured", "Sandbox: Podman not running", etc.).

• SandboxPrereqsModal — implements workspace::ModalView. Renders the two status rows + the install instructions from the data crate, with a per-step Copy button (writes to clipboard via cx.write_to_clipboard(ClipboardItem::new_string(...))) and a Refresh button that re-runs the probe.

init(cx) is the single entry point: registers the global, kicks off the first probe, and uses cx.observe_new to wire the OpenSandboxPrereqs action into every workspace as it opens.

Severity → color mapping

State	Color	Tooltip
Podman = Missing	red (Color::Error)	"Sandbox: Podman not installed"
Podman = InstalledNotRunning	red	"Sandbox: Podman not running"
Podman = Ready, Gvisor = NotConfigured	amber (Color::Warning)	"Sandbox: gVisor not configured"
Podman = Ready, Gvisor = Available / NotApplicable	green (Color::Success)	"Sandbox: ready"
no probe completed yet	muted	"Sandbox: checking…"

The NotApplicable case is Windows — there's no gVisor path on Windows today, so Podman alone counts as the satisfied state. The user gets a different tooltip pre-merge once we land tool gating; the visibility layer is correct either way.

Wire-up

Two-line edit in crates/paddleboard/src/main.rs (call init right after gpui_tokio::init, since the probe needs tokio's handle in scope).

Five-line edit in crates/paddleboard/src/zed.rs:initialize_workspace to instantiate the status item and register it via status_bar.add_right_item. Both edits tagged with // PaddleBoard: comments so future upstream merges keep the change.

What's not in this PR (PR-C)

• Tool gating: sandbox_tool, sandbox_service_tool, and sandboxed_stdio_transport still launch podman without checking the cached prereq status. A user with no Podman installed sees a confusing process-not-found error instead of the modal.
• Settings: no sandbox.on_missing_runtime policy (block / fall_back_to_host / warn_once) yet.
• No setting to disable the status indicator.

PR-C is the larger piece — it touches three tool entry points and has policy implications worth designing carefully.

Verification

• cargo check -p paddleboard — clean.
• cargo build -p paddleboard — clean (exit 0).
• ./script/clippy -p paddleboard_sandbox_prereqs_ui -p paddleboard_sandbox_prereqs — clean.
• Pre-existing llm_picker clippy failure on main is unrelated to this PR — confirmed by stashing changes and rerunning.
• Not interactively driven yet. The status item and modal compile and pass lint, but I haven't clicked through the UI myself in a running editor. Smoke test before merging — at minimum, confirm: (1) the icon appears in the right of the status bar after launch, (2) the tooltip is accurate, (3) clicking opens the modal, (4) Refresh re-probes (the icon should briefly flash to the muted "checking" state), (5) Copy buttons copy correct commands.

Diffstat

8 files changed, 436 insertions(+)

Test plan

• Build + launch PaddleBoard.
• Status bar (right side) shows a Box icon with severity color matching paddleboard --check-sandbox output.
• Hover → tooltip describes the state.
• Click icon → modal opens with the install steps from PR-A.
• Copy buttons place the right command on the clipboard.
• Refresh button reruns the probe (icon → muted, then back).
• paddleboard::OpenSandboxPrereqs action in the command palette opens the same modal.

Release Notes:

• Added a sandbox prerequisites indicator to the status bar and an install-guidance modal explaining how to set up Podman + gVisor.