feat: boka push ingest and stale monitoring (todo 04)

Add token- and IP-protected ingest.php, boka status checks in monitor.php,
and document the two-repo push workflow. Todo 04 marked complete.

Co-authored-by: Cursor <cursoragent@cursor.com>

server.env.example

@@ -19,6 +19,10 @@ ALERT_EMAIL=
 TARGETS_REVIEW_INTERVAL_DAYS=90
 MONITOR_INGEST_TOKEN=
 MONITOR_INGEST_URL=https://0012.de/ingest.php
+BOKA_IP=89.163.231.180
+BOKA_PUSH_STALE_MINUTES=15
+BOKA_DISK_WARN_PERCENT=85
+BOKA_BACKUP_STALE_HOURS=25
 
 # Optional
 TELEGRAM_BOT_TOKEN=