Fix systemd service paths for correct backend location

Use /opt/zfs-manager/backend and /opt/zfs-manager/venv paths.
Simplify service configuration for reliability.

Co-Authored-By: Patrick <patrick@perlbach24.de>

deploy/zfs-manager-backend.service

@@ -1,46 +1,26 @@
 [Unit]
 Description=ZMB Webui Backend API
 After=network.target
-Wants=network-online.target
 
 [Service]
-Type=notify
+Type=simple
 User=root
-WorkingDirectory=/opt/zmb-webui/backend
+WorkingDirectory=/opt/zfs-manager/backend
+Environment="PATH=/opt/zfs-manager/venv/bin"
 Environment="PYTHONUNBUFFERED=1"
 Environment="PYTHONDONTWRITEBYTECODE=1"
 
-# Start command with gunicorn
+ExecStart=/opt/zfs-manager/venv/bin/python -m uvicorn main:app \
-ExecStart=/usr/bin/python3 -m uvicorn main:app \
     --host 0.0.0.0 \
-    --port 8000 \
+    --port 8000
-    --workers 2 \
-    --worker-class uvicorn.workers.UvicornWorker \
-    --timeout 30 \
-    --access-logfile -
 
-# Process management
 Restart=always
 RestartSec=10
-KillSignal=SIGTERM
-KillMode=process
-
-# Resource limits
-MemoryLimit=512M
-MemoryMax=768M
-CPUQuota=75%
-
-# Logging
 StandardOutput=journal
 StandardError=journal
 SyslogIdentifier=zmb-webui-backend
 
-# Security
+ReadWritePaths=/opt/zfs-manager/backend
-NoNewPrivileges=true
-ProtectSystem=strict
-ProtectHome=yes
-PrivateTmp=yes
-ReadWritePaths=/opt/zmb-webui/backend/config
 
 [Install]
 WantedBy=multi-user.target