Add custom image handling and access policy management

- Implement tests for custom KVM and LXC image creation, ensuring invalid sources and architecture mismatches are rejected.
- Introduce access policy management in CLI, allowing configuration of allowed sources and trusted proxies.
- Add NAT network configuration with validation for RFC1918 compliance and subnet parsing.
- Create panel access policy management, including normalization and evaluation of access decisions based on client IPs and forwarded headers.
- Develop middleware for enforcing access policies in the server, returning appropriate responses for allowed and denied requests.
- Enhance custom image downloading and validation, ensuring integrity and security of downloaded root filesystem archives.
- Include comprehensive tests for all new functionalities to ensure reliability and correctness.

backend/main.go

@@ -27,6 +27,7 @@ func main() {
 	isServerMode := false
 	isCliMode := false
 	noWebAutostart := false
+	isAccessPolicyCommand := len(os.Args) > 1 && os.Args[1] == "access-policy"
 	for _, arg := range os.Args[1:] {
 		if arg == "server" || arg == "-s" || arg == "--server" {
 			isServerMode = true
@@ -48,6 +49,14 @@ func main() {
 	}
 	_ = cfg
 
+	if isAccessPolicyCommand {
+		if err := cli.RunAccessPolicyCommand(os.Args[2:]); err != nil {
+			fmt.Fprintf(os.Stderr, "Access policy error: %v\n", err)
+			os.Exit(1)
+		}
+		return
+	}
+
 	if isServerMode || (!isTerminal && !isCliMode) {
 		installShutdownStateCapture()