Add webhook config (DB/env), JSON POST on events/problems, settings API, Settings UI section, and notify_dispatch for multi-channel ingest. Co-authored-by: Cursor <cursoragent@cursor.com>
Store notification_channels (migration 004), effective config DB over env, PUT/test API endpoints, Settings form, and pass db session into ingest notify. Co-authored-by: Cursor <cursoragent@cursor.com>