Claude desktop 1.7196.0 (macOS) bounces in dock, no window, exits silently after upgrade

Environment

• macOS 15.6 (Darwin 25.3.0), Apple Silicon M2 Pro
• Claude desktop 1.7196.0 (broken), 1.6259.1 (working)
• Downloaded via Firefox — quarantine flag present

Behavior

After upgrading to 1.7196.0, Claude.app bounces in the dock and exits without showing any window. No crash report generated.

Diagnosis

• Quarantine flag (com.apple.quarantine) was set — removed it, did not fix the issue
• Process spawns (2 procs, normal memory) but bridge-state.json shows accountId: null
• App achieves frontmost status (count of windows = 1) but window never renders
• LSExceptions shared instance invalidated for timeout in system log — LaunchServices timed out opening a URL (likely OAuth browser callback)
• Clean exit sequence in logs, no crash
• stderr shows only non-fatal warnings (MaxListenersExceeded, DEP0169)

Fix

Downgrading to 1.6259.1 resolves the issue immediately. App launches, window appears, cowork link present.

Likely root cause

The login/OAuth flow in 1.7196.0 silently fails (LaunchServices timeout on URL open) and the app exits instead of showing an error or retry UI.