"feat: Update admin UI layout in backend"

backend/app/app.py

@@ -1656,6 +1656,219 @@ def admin_page():
         logs=logs
     )
 
+# ===== ERROR MONITORING SYSTEM =====
+
+@app.route("/api/admin/system-health", methods=['GET'])
+@login_required
+def api_admin_system_health():
+    """API-Endpunkt für System-Gesundheitscheck."""
+    if not current_user.is_admin:
+        return jsonify({"error": "Berechtigung verweigert"}), 403
+    
+    db_session = get_db_session()
+    critical_errors = []
+    warnings = []
+    
+    try:
+        # 1. Datenbank-Schema-Integrität prüfen
+        try:
+            # Test verschiedene kritische Tabellen und Spalten
+            db_session.execute("SELECT COUNT(*) FROM guest_requests WHERE duration_minutes IS NOT NULL")
+            schema_integrity = "OK"
+        except Exception as e:
+            critical_errors.append({
+                "type": "database_schema",
+                "message": f"Datenbank-Schema-Fehler: {str(e)}",
+                "severity": "critical",
+                "suggested_fix": "Datenbank-Migration ausführen",
+                "timestamp": datetime.now().isoformat()
+            })
+            schema_integrity = "FEHLER"
+        
+        # 2. Prüfe kritische Spalten in wichtigen Tabellen
+        schema_checks = [
+            ("guest_requests", "duration_minutes"),
+            ("guest_requests", "file_name"),
+            ("guest_requests", "processed_by"),
+            ("users", "updated_at"),
+            ("jobs", "duration_minutes")
+        ]
+        
+        missing_columns = []
+        for table, column in schema_checks:
+            try:
+                db_session.execute(f"SELECT {column} FROM {table} LIMIT 1")
+            except Exception:
+                missing_columns.append(f"{table}.{column}")
+        
+        if missing_columns:
+            critical_errors.append({
+                "type": "missing_columns",
+                "message": f"Fehlende Datenbank-Spalten: {', '.join(missing_columns)}",
+                "severity": "critical",
+                "suggested_fix": "python utils/database_schema_migration.py ausführen",
+                "timestamp": datetime.now().isoformat(),
+                "details": missing_columns
+            })
+        
+        # 3. Prüfe auf wiederkehrende Datenbankfehler in den Logs
+        import os
+        log_file = os.path.join("logs", "app", f"myp_app_{datetime.now().strftime('%Y_%m_%d')}.log")
+        recent_db_errors = 0
+        
+        if os.path.exists(log_file):
+            try:
+                with open(log_file, 'r', encoding='utf-8') as f:
+                    last_lines = f.readlines()[-100:]  # Letzte 100 Zeilen
+                    for line in last_lines:
+                        if "OperationalError" in line or "no such column" in line:
+                            recent_db_errors += 1
+            except Exception:
+                pass
+        
+        if recent_db_errors > 5:
+            critical_errors.append({
+                "type": "frequent_db_errors",
+                "message": f"{recent_db_errors} Datenbankfehler in letzter Zeit erkannt",
+                "severity": "high",
+                "suggested_fix": "System-Logs überprüfen und Migration ausführen",
+                "timestamp": datetime.now().isoformat()
+            })
+        
+        # 4. Prüfe Drucker-Konnektivität
+        offline_printers = db_session.query(Printer).filter(
+            Printer.status == "offline",
+            Printer.active == True
+        ).count()
+        
+        if offline_printers > 0:
+            warnings.append({
+                "type": "printer_offline",
+                "message": f"{offline_printers} aktive Drucker sind offline",
+                "severity": "warning",
+                "suggested_fix": "Drucker-Status überprüfen",
+                "timestamp": datetime.now().isoformat()
+            })
+        
+        # 5. System-Performance Metriken
+        import psutil
+        cpu_usage = psutil.cpu_percent(interval=1)
+        memory_usage = psutil.virtual_memory().percent
+        disk_usage = psutil.disk_usage('/').percent
+        
+        if cpu_usage > 90:
+            warnings.append({
+                "type": "high_cpu",
+                "message": f"Hohe CPU-Auslastung: {cpu_usage:.1f}%",
+                "severity": "warning",
+                "suggested_fix": "System-Ressourcen überprüfen",
+                "timestamp": datetime.now().isoformat()
+            })
+        
+        if memory_usage > 85:
+            warnings.append({
+                "type": "high_memory",
+                "message": f"Hohe Speicher-Auslastung: {memory_usage:.1f}%",
+                "severity": "warning",
+                "suggested_fix": "Speicher-Verbrauch optimieren",
+                "timestamp": datetime.now().isoformat()
+            })
+        
+        # 6. Letzte Migration info
+        try:
+            backup_dir = os.path.join("database", "backups")
+            if os.path.exists(backup_dir):
+                backup_files = [f for f in os.listdir(backup_dir) if f.endswith('.backup')]
+                if backup_files:
+                    latest_backup = max(backup_files, key=lambda x: os.path.getctime(os.path.join(backup_dir, x)))
+                    last_migration = latest_backup.replace('.backup', '').replace('myp.db.backup_', '')
+                else:
+                    last_migration = "Keine Backups gefunden"
+            else:
+                last_migration = "Backup-Verzeichnis nicht gefunden"
+        except Exception:
+            last_migration = "Unbekannt"
+        
+        return jsonify({
+            "success": True,
+            "health_status": "critical" if critical_errors else ("warning" if warnings else "healthy"),
+            "critical_errors": critical_errors,
+            "warnings": warnings,
+            "schema_integrity": schema_integrity,
+            "last_migration": last_migration,
+            "recent_errors_count": recent_db_errors,
+            "system_metrics": {
+                "cpu_usage": cpu_usage,
+                "memory_usage": memory_usage,
+                "disk_usage": disk_usage
+            },
+            "timestamp": datetime.now().isoformat()
+        })
+        
+    except Exception as e:
+        app_logger.error(f"Fehler beim System-Gesundheitscheck: {str(e)}")
+        return jsonify({
+            "success": False,
+            "error": "Fehler beim System-Gesundheitscheck",
+            "critical_errors": [{
+                "type": "system_check_failed",
+                "message": f"System-Check fehlgeschlagen: {str(e)}",
+                "severity": "critical",
+                "suggested_fix": "System-Logs überprüfen",
+                "timestamp": datetime.now().isoformat()
+            }]
+        }), 500
+    finally:
+        db_session.close()
+
+@app.route("/api/admin/fix-errors", methods=['POST'])
+@login_required 
+def api_admin_fix_errors():
+    """API-Endpunkt um automatische Fehler-Reparatur auszuführen."""
+    if not current_user.is_admin:
+        return jsonify({"error": "Berechtigung verweigert"}), 403
+    
+    try:
+        # Automatische Migration ausführen
+        import subprocess
+        import sys
+        
+        # Migration in separatem Prozess ausführen
+        result = subprocess.run(
+            [sys.executable, "utils/database_schema_migration.py"],
+            cwd=os.path.dirname(os.path.abspath(__file__)),
+            capture_output=True,
+            text=True,
+            timeout=60
+        )
+        
+        if result.returncode == 0:
+            app_logger.info(f"Automatische Migration erfolgreich ausgeführt von Admin {current_user.email}")
+            return jsonify({
+                "success": True,
+                "message": "Automatische Reparatur erfolgreich durchgeführt",
+                "details": result.stdout
+            })
+        else:
+            app_logger.error(f"Automatische Migration fehlgeschlagen: {result.stderr}")
+            return jsonify({
+                "success": False,
+                "error": "Automatische Reparatur fehlgeschlagen",
+                "details": result.stderr
+            }), 500
+            
+    except subprocess.TimeoutExpired:
+        return jsonify({
+            "success": False,
+            "error": "Migration-Timeout - Vorgang dauerte zu lange"
+        }), 500
+    except Exception as e:
+        app_logger.error(f"Fehler bei automatischer Reparatur: {str(e)}")
+        return jsonify({
+            "success": False,
+            "error": f"Fehler bei automatischer Reparatur: {str(e)}"
+        }), 500
+
 # Direkter Zugriff auf Logout-Route (für Fallback)
 @app.route("/logout", methods=["GET", "POST"])
 def logout_redirect():

backend/app/templates/admin.html

@@ -264,6 +264,62 @@
             </nav>
         </div>
 
+        <!-- Tab Content -->
+        <!-- Critical Errors Alert System -->
+        <div id="critical-errors-alert" class="bg-red-50 dark:bg-red-900/20 border border-red-200 dark:border-red-800 rounded-xl p-6 mb-8 hidden">
+            <div class="flex items-start space-x-4">
+                <div class="flex-shrink-0">
+                    <svg class="w-8 h-8 text-red-500 animate-pulse" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                        <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M12 9v2m0 4h.01m-6.938 4h13.856c1.54 0 2.502-1.667 1.732-2.5L13.732 4c-.77-.833-1.732-.833-2.464 0L4.35 16.5c-.77.833.192 2.5 1.732 2.5z"/>
+                    </svg>
+                </div>
+                <div class="flex-1">
+                    <h3 class="text-lg font-semibold text-red-800 dark:text-red-200 mb-2">
+                        🚨 Kritische Systemfehler erkannt
+                    </h3>
+                    <div id="error-list" class="space-y-2">
+                        <!-- Error items will be populated here -->
+                    </div>
+                    <div class="mt-4 flex space-x-3">
+                        <button id="fix-errors-btn" class="px-4 py-2 bg-red-600 text-white rounded-lg hover:bg-red-700 transition-colors text-sm font-medium">
+                            🔧 Automatisch reparieren
+                        </button>
+                        <button id="dismiss-errors-btn" class="px-4 py-2 bg-gray-200 dark:bg-gray-700 text-gray-800 dark:text-gray-200 rounded-lg hover:bg-gray-300 dark:hover:bg-gray-600 transition-colors text-sm font-medium">
+                            ❌ Verwerfen
+                        </button>
+                        <button id="view-error-details-btn" class="px-4 py-2 bg-blue-600 text-white rounded-lg hover:bg-blue-700 transition-colors text-sm font-medium">
+                            📊 Details anzeigen
+                        </button>
+                    </div>
+                </div>
+            </div>
+        </div>
+
+        <!-- Database Health Status -->
+        <div id="db-health-status" class="bg-white/60 dark:bg-slate-800/60 backdrop-blur-sm rounded-xl border border-slate-200 dark:border-slate-600 p-6 mb-8 shadow-lg">
+            <div class="flex items-center justify-between mb-4">
+                <h3 class="text-lg font-semibold text-slate-900 dark:text-white">🗄️ Datenbank-Gesundheitsstatus</h3>
+                <div class="flex items-center space-x-2">
+                    <div id="db-status-indicator" class="w-3 h-3 bg-green-400 rounded-full animate-pulse"></div>
+                    <span id="db-status-text" class="text-sm font-medium text-slate-600 dark:text-slate-400">Gesund</span>
+                </div>
+            </div>
+            <div class="grid grid-cols-1 md:grid-cols-3 gap-4">
+                <div class="bg-white/40 dark:bg-slate-700/40 rounded-lg p-4">
+                    <div class="text-sm text-slate-500 dark:text-slate-400">Letzte Migration</div>
+                    <div id="last-migration" class="text-lg font-semibold text-slate-900 dark:text-white">Lädt...</div>
+                </div>
+                <div class="bg-white/40 dark:bg-slate-700/40 rounded-lg p-4">
+                    <div class="text-sm text-slate-500 dark:text-slate-400">Schema-Integrität</div>
+                    <div id="schema-integrity" class="text-lg font-semibold text-green-600 dark:text-green-400">Lädt...</div>
+                </div>
+                <div class="bg-white/40 dark:bg-slate-700/40 rounded-lg p-4">
+                    <div class="text-sm text-slate-500 dark:text-slate-400">Letzte Fehler</div>
+                    <div id="recent-errors-count" class="text-lg font-semibold text-slate-900 dark:text-white">Lädt...</div>
+                </div>
+            </div>
+        </div>
+
         <!-- Tab Content -->
         <div class="bg-white/80 dark:bg-slate-800/80 backdrop-blur-xl rounded-3xl border border-white/20 dark:border-slate-700/50 shadow-xl overflow-hidden">