chore: add logrotate configuration for stacks-node

No log rotation was configured by default, allowing log files to
grow indefinitely. With debug logging producing ~500GB/hour, this
can fill disks rapidly. Adds a logrotate config that:
- Rotates daily and on 500MB size threshold
- Keeps 7 days of compressed history
- Uses copytruncate to avoid requiring a signal to the node

Install: cp contrib/init/stacks-logrotate /etc/logrotate.d/stacks-node

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

Author: huth-stacks

contrib/init/stacks-logrotate

@@ -0,0 +1,13 @@
+# Logrotate configuration for stacks-node
+# Install: cp contrib/init/stacks-logrotate /etc/logrotate.d/stacks-node
+
+/var/log/stacks-node/*.log {
+    daily
+    rotate 7
+    compress
+    delaycompress
+    missingok
+    notifempty
+    copytruncate
+    maxsize 500M
+}