release: 1.5.0: Send-log retention configurable in panel Settings

Send-log retention is configurable from panel **Settings** (global administrator); `SEND_LOG_RETENTION_DAYS` seeds the initial default only.
Added:
  - Panel **Settings** (global administrator): **Send log retention (days)** —
Changed:
  - Deliveries list and delivery detail pages show the configured retention

Full detail: CHANGELOG.md (1.5.0).

cmd/panel/httpserver.go

@@ -96,8 +96,9 @@ func newPanel(cfg config, st *store.Store) (*web.Server, error) {
 		DNSResolvers:           cfg.dnsResolvers,
 		RateLimitMessagesPerIP: cfg.rateLimitMessagesPerIP,
 		RateLimitWindowSeconds: cfg.rateLimitWindowSeconds,
-		RetryPolicy:            retryPolicy,
-		InboundEnabled:         cfg.inboundEnabled,
+		RetryPolicy:                 retryPolicy,
+		InboundEnabled:              cfg.inboundEnabled,
+		SendLogRetentionEnvDefault: cfg.retentionDays,
 	}, cfg.setupTokenPath)
 }