Use IDB for simulator screenshots instead of xcrun simctl

[obj-p]

Summary

Currently SimulatorManager.screenshot() shells out to xcrun simctl io <udid> screenshot to capture simulator screenshots. We should consider using IDB (iOS Development Bridge) instead for tighter integration and better reliability.

Motivation

• xcrun simctl screenshot runs as a separate process with pipe-based I/O, which has historically been prone to deadlock when stderr output exceeds the pipe buffer (~64KB)
• IDB provides a more direct programmatic interface to simulator services
• Tighter integration could reduce latency for screenshot capture, which matters for hot-reload feedback loops

Current implementation

SimulatorManager.screenshot() in Sources/PreviewsIOS/SimulatorManager.swift uses runAsync("/usr/bin/xcrun", arguments: ["simctl", "io", udid, "screenshot", ...]).

Proposed approach

Investigate using IDB's screenshot API (either via the IDB companion daemon or direct framework access) as a replacement for the simctl subprocess approach. This would align with how we already use CoreSimulator.framework directly for device management via SimulatorBridge.

[obj-p]

Resolved by #33 — direct IOSurface capture replaces xcrun simctl subprocess. Used IOSurface instead of IDB but achieves the same goal (eliminate pipe deadlocks, reduce latency).