feat(monitoring): complete monitoring pipeline and fix presentation flag persistence

add superadmin monitoring dashboard with protected route, menu entry, and monitoring data client
add monitoring overview API endpoint and improve log serialization/aggregation for dashboard use
extend listener health/log handling with robust status/event/timestamp normalization and screenshot payload extraction
improve screenshot persistence and retrieval (timestamp-aware uploads, latest screenshot endpoint fallback)
fix page_progress and auto_progress persistence/serialization across create, update, and detached occurrence flows
align technical and project docs to reflect implemented monitoring and no-version-bump backend changes
add documentation sync log entry and include minor compose env indentation cleanup

server/routes/clients.py

@@ -4,6 +4,7 @@ from flask import Blueprint, request, jsonify
 from server.permissions import admin_or_higher
 from server.mqtt_helper import publish_client_group, delete_client_group_message, publish_multiple_client_groups
 import sys
+from datetime import datetime, timezone
 sys.path.append('/workspace')
 
 clients_bp = Blueprint("clients", __name__, url_prefix="/api/clients")
@@ -284,21 +285,46 @@ def upload_screenshot(uuid):
     import os
     import base64
     import glob
-    from datetime import datetime
-
     session = Session()
     client = session.query(Client).filter_by(uuid=uuid).first()
     if not client:
         session.close()
         return jsonify({"error": "Client nicht gefunden"}), 404
-    session.close()
 
     try:
+        screenshot_timestamp = None
+
         # Handle JSON payload with base64-encoded image
         if request.is_json:
             data = request.get_json()
             if "image" not in data:
                 return jsonify({"error": "Missing 'image' field in JSON payload"}), 400
+
+            raw_timestamp = data.get("timestamp")
+            if raw_timestamp is not None:
+                try:
+                    if isinstance(raw_timestamp, (int, float)):
+                        ts_value = float(raw_timestamp)
+                        if ts_value > 1e12:
+                            ts_value = ts_value / 1000.0
+                        screenshot_timestamp = datetime.fromtimestamp(ts_value, timezone.utc)
+                    elif isinstance(raw_timestamp, str):
+                        ts = raw_timestamp.strip()
+                        if ts:
+                            if ts.isdigit():
+                                ts_value = float(ts)
+                                if ts_value > 1e12:
+                                    ts_value = ts_value / 1000.0
+                                screenshot_timestamp = datetime.fromtimestamp(ts_value, timezone.utc)
+                            else:
+                                ts_normalized = ts.replace("Z", "+00:00") if ts.endswith("Z") else ts
+                                screenshot_timestamp = datetime.fromisoformat(ts_normalized)
+                                if screenshot_timestamp.tzinfo is None:
+                                    screenshot_timestamp = screenshot_timestamp.replace(tzinfo=timezone.utc)
+                                else:
+                                    screenshot_timestamp = screenshot_timestamp.astimezone(timezone.utc)
+                except Exception:
+                    screenshot_timestamp = None
             
             # Decode base64 image
             image_data = base64.b64decode(data["image"])
@@ -314,7 +340,8 @@ def upload_screenshot(uuid):
         os.makedirs(screenshots_dir, exist_ok=True)
 
         # Store screenshot with timestamp to track latest
-        timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
+        now_utc = screenshot_timestamp or datetime.now(timezone.utc)
+        timestamp = now_utc.strftime("%Y%m%d_%H%M%S")
         filename = f"{uuid}_{timestamp}.jpg"
         filepath = os.path.join(screenshots_dir, filename)
 
@@ -326,6 +353,10 @@ def upload_screenshot(uuid):
         with open(latest_filepath, "wb") as f:
             f.write(image_data)
 
+        # Update screenshot receive timestamp for monitoring dashboard
+        client.last_screenshot_analyzed = now_utc
+        session.commit()
+
         # Cleanup: keep only last 20 timestamped screenshots per client
         pattern = os.path.join(screenshots_dir, f"{uuid}_*.jpg")
         existing_screenshots = sorted(glob.glob(pattern))
@@ -349,7 +380,10 @@ def upload_screenshot(uuid):
         }), 200
 
     except Exception as e:
+        session.rollback()
         return jsonify({"error": f"Failed to process screenshot: {str(e)}"}), 500
+    finally:
+        session.close()
 
 
 @clients_bp.route("/<uuid>", methods=["DELETE"])