Performance:
- HealthController: honor `:timeout` from `:redis` config (was hardcoded
2s) so the 503-when-unreachable test exits immediately
- DevicePollerBranches: drop `collect_events` window 1500ms → 100ms
(PubSub broadcasts are synchronous from `run_perform`)
- Towerops.Unused: cache xref analysis in `:persistent_term` keyed by
BEAM mtimes so repeated `mix unused` invocations skip re-analysis
- DiscoveryWorker: make wait_loop interval configurable via
`:discovery_wait_interval_ms` (25ms in tests vs 500ms in prod)
- ProfileWatcher: configurable `:profile_reloader` so tests can stub
the YAML reload instead of paying the full disk-load cost
- PingExecutor: tag the loopback test `:network` (it shells out to
`ping`); coverage already provided by 4 other `:network`-tagged tests
Flake fix:
- FrequencyChange tests used hardcoded `~U[2026-05-09 12:00:00Z]`,
which now falls outside the rule's 24h lookback window. Switched to
`DateTime.utc_now()` so scans stay inside the window regardless of
clock progression.
Added logging to identify which component is failing health checks:
- Log database and Redis status on each health check
- Log Redis errors with full error details
- This will help diagnose the production 503 errors
Create HealthController that returns 200 OK for health checks.
Route is outside browser pipeline to avoid SSL redirect and
authentication requirements.
