Performance:
- schedule_live: preload page once instead of get_schedule!/1 per row
- alert_live + alerts: DB-side status filter; Repo.aggregate counts replace length/Enum.count over 500-row fetches on every event
- dashboard_live: drop duplicate get_device_status_counts; cap active alerts to 20 + use count_active_alerts/1
- maintenance.active_windows_for_device: 3 round-trips collapsed into one query (per-site-id branch keeps Postgres parameter types unambiguous)
- sites.build_site_tree: O(N^2) -> O(N) via group_by(parent_site_id)
- accounts.sole_owner_organizations: single group_by + having instead of per-org Repo.aggregate loop
- agents + agent_live (org + admin): count_assigned_devices_batch/1 + count_agent_polling_targets/1 (no preloads)
- alert_digest_worker: list_alerts_by_ids/1 batches digest fetch
- gaiia: distinct: true at DB; limit 50 on bidirectional ilike
Indexes:
- maintenance_windows(organization_id, starts_at, ends_at) WHERE suppress_alerts = true
- alerts(check_id) WHERE resolved_at IS NULL
Antipatterns:
- agents.delete_agent_token: PubSub.broadcast moved outside Repo.transaction so a rollback no longer leaves subscribers acting on a non-existent deletion
- integrations_controller.to_atom_keys: replaced String.to_existing_atom on user-controlled JSON keys with explicit allowlist
- 9 Task.start callsites converted to Task.Supervisor.start_child(Towerops.TaskSupervisor, ...) so background DB writes survive shutdown (test-mode discovery shims left as-is for sandbox semantics)
