v0.7.3 - Reliable streams, dependable credits, and data controls

Chat and analysis now reconnect cleanly without losing output, credit handling is more dependable, and you can export or delete your account data on demand.

• Reconnecting to a running chat or analysis - after a refresh, in a second tab, or by re-opening it from the sidebar - restores the full response instead of dropping you mid-stream.
• More dependable credit handling: a charge or refund can no longer be double-applied or lost if a request is retried or interrupted.
• New privacy controls in your profile: export a full copy of your account data, and permanently delete your account (with a 30-day grace period before removal).
• Fixes to patent ingestion, preview, and translation.