Webapp: Dashboard analytics, integrations, and dev tools

Analytics dashboard, integrations infrastructure, and a developer toolbar added to the webapp.

• Dashboard with conversation activity, status breakdowns, and peak timing heatmap
• Auto-refreshes every 60 seconds with visible countdown
• Integrations page with OAuth, API key, and webhook infrastructure
• Org settings: upload logo, view online team members
• Developer toolbar for debugging WebSocket connections, API calls, and event logs