[Bug]: macOS: OpenScreen does not open while an Openscreen mcp stdio server is running #1214

Platform: macOS 26.5 (M1), CI build of main @ 0bed36852 (run 38581408372, notarized DMG). Found during the e2e pass logged in #1212.

Repro

1. Register the stdio server in an MCP client (/Applications/Openscreen.app/Contents/MacOS/Openscreen mcp) and keep its session open. For the strongest case, run one startRecording/stopRecording through it.
2. Quit the OpenScreen app (the GUI), leaving the MCP client running.
3. Open OpenScreen from Finder, the Dock or open /Applications/Openscreen.app.

Expected: the recording bar appears.

Actual: nothing opens. open exits 0 and no GUI process starts. With env flags, open prints "Application /Applications/Openscreen.app was already running". LaunchServices treats the mcp process (same bundle id) as the running app and activates it instead. lsappinfo showed that process as type="Foreground", in front, with its own OpenScreen icon in the Dock. A second mcp process that had not recorded was UIElement.

Impact: anyone using Claude Code or Codex with the stdio server cannot launch the app while the agent session is open. A Dock icon that does nothing is the only visible sign.

Workaround: open -n -a /Applications/Openscreen.app.

Likely direction: the mcp entry point should stay out of LaunchServices' "running app" slot. For example, keep it LSUIElement/prohibited activation, never transform it to a foreground app, even after it records. The CLI's record probably shares the same path.