0396acdc59
Phase 3 of distributed probing: - Add regions column to sites table for per-monitor probe affinity - Region-filtered probe assignments (empty regions = all probes) - New Nodes TUI tab showing connected probes with status/region/last-seen - Regions input field in site form for configuring probe affinity - Config-as-code support for regions (export/import/diff) - Prometheus upkeep_probe_up metric with per-node labels - Reindex TUI tabs: Sites, Alerts, Logs, Nodes, Users