feat: Add presence heartbeat for Matrix online status

- matrix-gateway: POST /internal/matrix/presence/online endpoint
- usePresenceHeartbeat hook with activity tracking
- Auto away after 5 min inactivity
- Offline on page close/visibility change
- Integrated in MatrixChatRoom component

services/node-registry/app/node1_prometheus.py

@@ -0,0 +1,87 @@
+"""
+Helper for reading real Prometheus metrics from NODE1 via SSH tunnel.
+Assumes tunnel exposes Prometheus locally (http://localhost:19090 by default).
+"""
+from __future__ import annotations
+
+import os
+from datetime import datetime
+from typing import Any, Dict, Optional
+
+import requests
+
+PROM_URL = os.getenv("NODE1_PROMETHEUS_URL", "http://localhost:19090")
+REQUEST_TIMEOUT = float(os.getenv("NODE1_PROMETHEUS_TIMEOUT", "2.5"))
+
+PROM_HEALTH_QUERY = 'up{job="prometheus"}'
+CPU_USAGE_QUERY = "100 - (avg(rate(node_cpu_seconds_total{mode=\"idle\"}[5m])) * 100)"
+MEMORY_USAGE_QUERY = "(1 - (avg(node_memory_MemAvailable_bytes) / avg(node_memory_MemTotal_bytes))) * 100"
+DISK_USAGE_QUERY = "(1 - (sum(node_filesystem_free_bytes{mountpoint=\"/\",fstype!~\"tmpfs|overlay\"}) / sum(node_filesystem_size_bytes{mountpoint=\"/\",fstype!~\"tmpfs|overlay\"}))) * 100"
+GPU_USAGE_QUERY = "avg(dcgm_gpu_utilization)"
+
+
+def prom_query(query: str) -> Optional[float]:
+    """Execute Prometheus instant query and return float value."""
+    try:
+        response = requests.get(
+            f"{PROM_URL}/api/v1/query",
+            params={"query": query},
+            timeout=REQUEST_TIMEOUT,
+        )
+        response.raise_for_status()
+        payload = response.json()
+        if payload.get("status") != "success":
+            return None
+        results = payload.get("data", {}).get("result", [])
+        if not results:
+            return None
+        # value structure: [timestamp, value]
+        value = float(results[0]["value"][1])
+        return value
+    except Exception:
+        return None
+
+
+def _clamp(value: Optional[float]) -> float:
+    if value is None:
+        return 0.0
+    return max(0.0, min(100.0, round(value, 2)))
+
+
+def get_node1_metrics() -> Dict[str, Any]:
+    """
+    Collect NODE1 metrics via Prometheus tunnel.
+    Returns structure compatible with system_metrics.get_all_metrics().
+    """
+    health = prom_query(PROM_HEALTH_QUERY)
+    if health is None:
+        return {
+            "success": False,
+            "error": "Prometheus reachable but returned no data for health query",
+            "source": PROM_URL,
+        }
+
+    cpu_percent = _clamp(prom_query(CPU_USAGE_QUERY))
+    mem_percent = _clamp(prom_query(MEMORY_USAGE_QUERY))
+    disk_percent = _clamp(prom_query(DISK_USAGE_QUERY))
+    gpu_percent = _clamp(prom_query(GPU_USAGE_QUERY))
+
+    metrics_available = any(value > 0 for value in [cpu_percent, mem_percent, disk_percent, gpu_percent])
+    message = None
+    if not metrics_available:
+        message = "node_exporter/DCGM метрики не знайдені, повертаємо значення за замовчуванням"
+
+    return {
+        "success": True,
+        "metrics_available": metrics_available,
+        "source": PROM_URL,
+        "timestamp": datetime.utcnow().isoformat() + "Z",
+        "message": message,
+        "metrics": {
+            "cpu": {"percent": cpu_percent},
+            "memory": {"percent": mem_percent},
+            "disk": {"percent": disk_percent},
+            "gpu": {"percent": gpu_percent},
+        },
+    }
+