fix: cap NATS JetStream streams to prevent OOM crash

WIRELESS_REGISTRATIONS stream had a 256MB MaxBytes cap in a 256MB
container — guaranteed to crash under load. ALERT_EVENTS and
OPERATION_EVENTS had no byte limit at all.

- Reduce WIRELESS_REGISTRATIONS MaxBytes from 256MB to 128MB
- Add 16MB MaxBytes cap to ALERT_EVENTS and OPERATION_EVENTS
- Bump NATS container memory limit from 256MB to 384MB
- Add restart: unless-stopped to NATS in base compose
- Bump version to 9.8.2

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

poller/internal/bus/publisher.go

@@ -163,7 +163,7 @@ func NewPublisher(natsURL string) (*Publisher, error) {
 		Name:     "WIRELESS_REGISTRATIONS",
 		Subjects: []string{"wireless.registrations.>"},
 		MaxAge:   30 * 24 * time.Hour,    // 30-day retention
-		MaxBytes: 256 * 1024 * 1024,      // 256MB cap
+		MaxBytes: 128 * 1024 * 1024,      // 128MB cap
 		Discard:  jetstream.DiscardOld,
 	})
 	if err != nil {