[client] Add opt-in --allow-server-rdp flag, reuse SSH ACL, dynamic DLL registration

- Add ServerRDPAllowed field to daemon proto, EngineConfig, and profile config
- Add --allow-server-rdp flag to `netbird up` (opt-in, defaults to false)
- Wire RDP server start/stop in engine based on the flag
- Reuse SSH ACL (SSHAuth proto) for RDP authorization via sshauth.Authorizer
- Register/unregister credential provider COM DLL dynamically when flag is toggled
- Ship DLL alongside netbird.exe, register via regsvr32 at runtime (not install time)
- Update SetConfig tests to cover the new field

https://claude.ai/code/session_01C38bCDyYzLgxYLVwJkcUng

client/internal/profilemanager/config.go

@@ -64,6 +64,7 @@ type ConfigInput struct {
 	StateFilePath                 string
 	PreSharedKey                  *string
 	ServerSSHAllowed              *bool
+	ServerRDPAllowed              *bool
 	EnableSSHRoot                 *bool
 	EnableSSHSFTP                 *bool
 	EnableSSHLocalPortForwarding  *bool
@@ -114,6 +115,7 @@ type Config struct {
 	RosenpassEnabled              bool
 	RosenpassPermissive           bool
 	ServerSSHAllowed              *bool
+	ServerRDPAllowed              *bool
 	EnableSSHRoot                 *bool
 	EnableSSHSFTP                 *bool
 	EnableSSHLocalPortForwarding  *bool
@@ -415,6 +417,21 @@ func (config *Config) apply(input ConfigInput) (updated bool, err error) {
 		updated = true
 	}
 
+	if input.ServerRDPAllowed != nil {
+		if config.ServerRDPAllowed == nil || *input.ServerRDPAllowed != *config.ServerRDPAllowed {
+			if *input.ServerRDPAllowed {
+				log.Infof("enabling RDP passthrough")
+			} else {
+				log.Infof("disabling RDP passthrough")
+			}
+			config.ServerRDPAllowed = input.ServerRDPAllowed
+			updated = true
+		}
+	} else if config.ServerRDPAllowed == nil {
+		config.ServerRDPAllowed = util.False()
+		updated = true
+	}
+
 	if input.EnableSSHRoot != nil && input.EnableSSHRoot != config.EnableSSHRoot {
 		if *input.EnableSSHRoot {
 			log.Infof("enabling SSH root login")