- New route /api/v1/log-insights: analyzes audit logs + security events
- Shows top IPs with request counts, failures, and top actions
- Plain English insights (heavy users, auth failures, security alerts)
- Summary stats: total requests, unique IPs, failed actions
- Storage info showing log file sizes and entry counts
- New route POST /api/v1/log-insights/dispose: preview-then-confirm cleanup
- First call shows what would be deleted (preview mode)
- Second call with confirm:true actually deletes
- Configurable retention period (default 30 days)
- Frontend panel with modal UI showing insights as cards
- Period selector (1h, 6h, 24h, 7d)
- Top visitors table with IP, requests, failures, actions, last seen
- Storage info footer
- Clean Old Logs button with preview confirmation dialog
- Wired into app.js and dashboard navbar (🔍 Insights button)
- Addresses QA issue: users need to see who is accessing before cleanup
