Ava API

API scaffold ready. Available mock endpoints:

• /api/health
• /api/auth/session
• /api/conversations
• /api/conversations/:id
• /api/messages (POST)
• /api/handoff/request (POST)
• /api/handoff/queue
• /api/handoff/claim (POST)
• /api/handoff/resolve (POST)
• /api/realtime/events
• /api/realtime/typing (POST)