No more duplicate interviews or broken messages

• No more duplicate interviews Background sign-in refreshes no longer restart interviews, so participants won't get duplicate sessions or restarted voice conversations.
• Outbound voice calls wait to greet The AI no longer speaks immediately on outbound calls — it waits for the recipient to speak first, which feels more natural for voice conversations.

No more corrupted chat messages Added a guard against rapid double-clicks and overlapping send-or-regenerate actions across all chat surfaces, preventing message corruption.