Added data retention and node cleanup

.env.example

@@ -141,3 +141,35 @@ WEBHOOK_MESSAGE_SECRET=
 WEBHOOK_TIMEOUT=10.0
 WEBHOOK_MAX_RETRIES=3
 WEBHOOK_RETRY_BACKOFF=2.0
+
+# ===================
+# Data Retention Settings
+# ===================
+
+# Enable automatic cleanup of old event data
+# When enabled, the collector runs periodic cleanup to delete old events
+# Default: true
+DATA_RETENTION_ENABLED=true
+
+# Number of days to retain event data (advertisements, messages, telemetry, etc.)
+# Events older than this are deleted during cleanup
+# Default: 30 days
+DATA_RETENTION_DAYS=30
+
+# Hours between automatic cleanup runs (applies to both events and nodes)
+# Default: 24 hours (once per day)
+DATA_RETENTION_INTERVAL_HOURS=24
+
+# ===================
+# Node Cleanup Settings
+# ===================
+
+# Enable automatic cleanup of inactive nodes
+# Nodes that haven't been seen (last_seen) for the specified period are removed
+# Nodes with last_seen=NULL (never seen on network) are NOT removed
+# Default: true
+NODE_CLEANUP_ENABLED=true
+
+# Remove nodes not seen for this many days (based on last_seen field)
+# Default: 7 days
+NODE_CLEANUP_DAYS=7