Fix 8 issues from code review

- ha-poller: replace recursive main() retry with while loop (stack overflow fix)
- ha-poller: advance last_push on empty HA response (log spam fix)
- ha-poller: use datetime.now(timezone.utc) instead of deprecated utcnow()
- ping-probe: always call update_status() unconditionally so offline devices register as offline
- agent.php: heartbeat reads status from payload instead of hardcoding 'online'
- phone-probe: delegate JSON building to python3 (bash concatenation injection fix)
- netscan + phone-probe: read registration key from /etc/jarvis-agent/reg-key
- admin/index.php: sync ha_list skipDomains with ha.php (14 missing domains added)
- facts_collector: self-check JARVIS via 127.0.0.1 instead of Cloudflare hairpin

agent/pve1-probes/jarvis-netscan.sh

@@ -4,7 +4,11 @@
 
 JARVIS_URL="http://10.48.200.211"
 JARVIS_HOST="jarvis.orbishosting.com"
-REG_KEY="f846a9aaf7ce9a61742c63c87c4186052a71d2a580c65518"
+REG_KEY=$(cat /etc/jarvis-agent/reg-key 2>/dev/null)
+if [ -z "$REG_KEY" ]; then
+    echo "$(date): ERROR: /etc/jarvis-agent/reg-key not found" >&2
+    exit 1
+fi
 SUBNET="10.48.200.0/24"
 
 TMPFILE=$(mktemp)