Prerelease Alpha 46 — data export, account delete, crash fix

Privacy controls are now first-class. Settings includes a new Your Data section where you can export your Rush data and start account deletion without leaving the app.

Delete means local cleanup too. Once the server confirms the delete request, Rush wipes local sessions, agents, keys, and user.yaml before signing you out. A pending-deletion banner gives you a 30-day window to cancel.

Alpha 46 also fixes a launch regression. A sandboxed preload import could fail before the window.rush bridge mounted, crashing the app on every launch. The guards are now inlined so the app opens cleanly again.