sim: fix macOS MetaDrive support

Fix MetaDrive simulator support on macOS. Two issues prevented the simulator from running:

1. processNotRunning errors: logcatd and proclogd are Android-only processes that trigger engagement-blocking errors on macOS. These are now blocked in the simulation launch script.

2. CoreFoundation fork crash: After the Qt→raylib UI migration, os.forkpty() in unblock_stdout() crashes on macOS because CoreFoundation/AppKit doesn't allow fork() after initialization. This is now skipped on macOS.

Related bounty: Get MetaDrive simulator working on macOS

Verification

Tested on macOS 14 (M3):

• MetaDrive simulator launches successfully
• openpilot UI displays correctly with BIG=1
• openpilot engages and drives in simulation
• Verified simulation completes laps without crashes

Known Issue

Camera view has a rendering artifact (diagonal distortion in corner) - this is an upstream panda3d/MetaDrive issue on macOS, not an openpilot bug.