feat(core): Add 3-tier stats persistence and LuCI tree navigation
Stats Persistence Layer:
- Add secubox-stats-persist daemon for never-trashed stats
- 3-tier caching: RAM (/tmp) → buffer → persistent (/srv)
- Hourly snapshots (24h), daily aggregates (30d)
- Boot recovery from persistent storage
- Heartbeat line: real-time 60-sample buffer (3min window)
- Evolution view: combined influence score over time
RPCD Stats Module:
- get_timeline: 24h evolution for all collectors
- get_evolution: combined influence score timeline
- get_heartbeat_line: real-time 3min buffer
- get_stats_status: persistence status and current values
- get_history: historical data per collector
- get_collector_cache: current cache value
LuCI Tree Navigation:
- Add clickable tree of all 60+ SecuBox LuCI apps
- Organized by category: Security, Network, Monitoring, Services, etc.
- Real-time search filter
- Available at /secubox-public/luci-tree and /admin/secubox/luci-tree
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>