1. load_dashboard.py: get_today_usage/amount and trend functions now
filter out accounting_status='failed' records so failed transactions
are not counted as successful.
2. stat_errors.ui: added click bind to navigate to llmage failed
accounting records page (app.sage_main_content target).
- Add get_usage_trend() and get_amount_trend() functions for day-over-day comparison
- Display trend arrows (up/down/flat) with percentage change in stat_today_usage and stat_today_amount
- Add colored left borders to all stat cards for visual distinction:
- Blue: usage, total users
- Purple: amount, total orgs
- Green: active users, new users this month
- Cyan: concurrent users
- Red: errors
- Enhance visual hierarchy with accent colors matching SVG icons