Custom-built error handler for the web channel that shows a tabbed debug
dashboard (exception, request context, environment, SQL queries) in dev mode
and a clean branded error page with copyable request ID in prod mode.
All errors are logged as JSON lines to storage/logs/errors/ for lookup by
request ID. Uses the project's design tokens for visual consistency.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
