feat(agent-installer): drop Gateway URL override field from dialog

The dialog's optional "Gateway URL (advanced)" textbox encouraged a
deployment pattern the Gateway explicitly doesn't support: pointing the
agent at the Gateway via a different host/IP than the canonical
externally-reachable `Hostname` configured on the Gateway side. Per the
team's design, a Gateway has one canonical hostname (the one its HTTPS
cert validates against); multiple agent-facing identities are not
supported.

Removed:

- `AGENT_TUNNEL_GATEWAY_URL` MSI public property (Program.cs, AgentProperties.cs)
- `--gateway` argument forwarding in CA.EnrollAgentTunnel (CustomActions.cs)
- gatewayUrl textbox + label + hint label from AgentTunnelDialog
  (.cs + .Designer.cs), reduced TableLayoutPanel RowCount from 14 to 11
- `AgentTunnelDlgGatewayUrlLabel` / `AgentTunnelDlgGatewayUrlHint`
  localization strings (en-us + fr-fr .wxl)

The JWT's `jet_gw_url` claim remains the sole source of truth for the
agent's enrollment endpoint and persisted tunnel identity. The CLI
`--gateway` flag on `agent.exe up` is still available for dev/operator
scenarios as an enrollment-transport override only (identity stays
anchored to the JWT host).

Author: irvingoujAtDevolution

package/AgentWindowsManaged/Actions/AgentActions.cs

@@ -294,7 +294,6 @@ internal static class AgentActions
         UsesProperties = string.Join(";", new[]
         {
             AgentProperties.AgentTunnelEnrollmentString,
-            AgentProperties.AgentTunnelGatewayUrl,
             AgentProperties.AgentTunnelAgentName,
             AgentProperties.AgentTunnelAdvertiseSubnets,
             AgentProperties.AgentTunnelAdvertiseDomains,

package/AgentWindowsManaged/Actions/CustomActions.cs

@@ -325,7 +325,6 @@ public static ActionResult EnrollAgentTunnel(Session session)
             string enrollmentString = session.Property(AgentProperties.AgentTunnelEnrollmentString)?.Trim() ?? string.Empty;
             string subnetsArg = session.Property(AgentProperties.AgentTunnelAdvertiseSubnets)?.Trim() ?? string.Empty;
             string domainsArg = session.Property(AgentProperties.AgentTunnelAdvertiseDomains)?.Trim() ?? string.Empty;
-            string gatewayUrlArg = session.Property(AgentProperties.AgentTunnelGatewayUrl)?.Trim() ?? string.Empty;
             string agentNameArg = session.Property(AgentProperties.AgentTunnelAgentName)?.Trim() ?? string.Empty;
 
             ActionResult Fail(string msg)
@@ -361,7 +360,6 @@ ActionResult Fail(string msg)
                 }
 
                 string arguments = $"up --enrollment-string \"{enrollmentString}\"";
-                if (gatewayUrlArg.Length != 0) arguments += $" --gateway \"{gatewayUrlArg}\"";
                 if (resolvedName.Length != 0) arguments += $" --name \"{resolvedName}\"";
                 if (subnetsArg.Length != 0) arguments += $" --advertise-subnets \"{subnetsArg}\"";
 

package/AgentWindowsManaged/Dialogs/AgentTunnelDialog.Designer.cs

@@ -25,7 +25,6 @@ public override bool ToProperties()
         Runtime.Session[AgentProperties.AgentTunnelAgentName] = agentName.Text.Trim();
         Runtime.Session[AgentProperties.AgentTunnelAdvertiseSubnets] = advertiseSubnets.Text.Trim();
         Runtime.Session[AgentProperties.AgentTunnelAdvertiseDomains] = advertiseDomains.Text.Trim();
-        Runtime.Session[AgentProperties.AgentTunnelGatewayUrl] = gatewayUrl.Text.Trim();
 
         return true;
     }
@@ -38,7 +37,6 @@ public override void OnLoad(object sender, EventArgs e)
         agentName.Text = Runtime.Session.Property(AgentProperties.AgentTunnelAgentName);
         advertiseSubnets.Text = Runtime.Session.Property(AgentProperties.AgentTunnelAdvertiseSubnets);
         advertiseDomains.Text = Runtime.Session.Property(AgentProperties.AgentTunnelAdvertiseDomains);
-        gatewayUrl.Text = Runtime.Session.Property(AgentProperties.AgentTunnelGatewayUrl);
 
         base.OnLoad(sender, e);
     }

package/AgentWindowsManaged/Dialogs/AgentTunnelDialog.cs

@@ -352,7 +352,6 @@ static void Main()
         // Agent tunnel properties: must be declared Secure so the values set in the wizard UI
         // survive the UAC boundary and reach the deferred CA via CustomActionData.
         projectProperties.Add(new Property(AgentProperties.AgentTunnelEnrollmentString, "") { Hidden = true, Secure = true });
-        projectProperties.Add(new Property(AgentProperties.AgentTunnelGatewayUrl, "") { Secure = true });
         projectProperties.Add(new Property(AgentProperties.AgentTunnelAgentName, "") { Secure = true });
         projectProperties.Add(new Property(AgentProperties.AgentTunnelAdvertiseSubnets, "") { Secure = true });
         projectProperties.Add(new Property(AgentProperties.AgentTunnelAdvertiseDomains, "") { Secure = true });

package/AgentWindowsManaged/Program.cs

@@ -31,13 +31,6 @@ internal partial class AgentProperties
         /// </summary>
         public static string AgentTunnelAdvertiseDomains = "AGENT_TUNNEL_ADVERTISE_DOMAINS";
 
-        /// <summary>
-        /// Optional gateway URL override. When set, the agent uses this URL instead of the JWT's
-        /// jet_gw_url claim. Useful when the JWT was minted with a URL that isn't reachable from
-        /// the agent's network (e.g. DVLS embedded "localhost" but the agent is remote).
-        /// </summary>
-        public static string AgentTunnelGatewayUrl = "AGENT_TUNNEL_GATEWAY_URL";
-
         /// <summary>
         /// Optional agent display name. Resolution order at install time:
         /// dialog value (if non-empty) > JWT's jet_agent_name claim (if present) > local computer name.

package/AgentWindowsManaged/Properties/AgentProperties.cs

@@ -69,6 +69,4 @@ If it appears minimized then active it from the taskbar.</String>
                 <String Id="AgentTunnelDlgDomainsHint">Comma-separated DNS suffixes the agent can resolve, e.g. corp.example.com, lab.example.com. Leave blank to skip.</String>
                 <String Id="AgentTunnelDlgAgentNameLabel">Agent name (optional):</String>
                 <String Id="AgentTunnelDlgAgentNameHint">Identifier for this agent. Leave blank to use the name in the JWT, or the local computer name as a final fallback.</String>
-                <String Id="AgentTunnelDlgGatewayUrlLabel">Gateway URL (advanced, optional):</String>
-                <String Id="AgentTunnelDlgGatewayUrlHint">Override the URL embedded in the enrollment JWT. Leave blank to use the JWT's value.</String>
                     </WixLocalization>

package/AgentWindowsManaged/Resources/DevolutionsAgent_en-us.wxl

@@ -14,8 +14,6 @@
                 <String Id="AgentTunnelDlgDomainsHint">Suffixes DNS séparés par des virgules que l'agent peut résoudre, p. ex. corp.example.com, lab.example.com. Laissez vide pour ignorer.</String>
                 <String Id="AgentTunnelDlgAgentNameLabel">Nom de l'agent (facultatif) :</String>
                 <String Id="AgentTunnelDlgAgentNameHint">Identifiant de cet agent. Laissez vide pour utiliser le nom inscrit dans le JWT, ou le nom de l'ordinateur local comme dernier recours.</String>
-                <String Id="AgentTunnelDlgGatewayUrlLabel">URL de la passerelle (avancé, facultatif) :</String>
-                <String Id="AgentTunnelDlgGatewayUrlHint">Remplace l'URL incluse dans le JWT d'enrôlement. Laissez vide pour utiliser la valeur du JWT.</String>
                 <String Id="Language">1036</String>
                 <String Id="ProductDescription">Service à l’échelle du système pour étendre les fonctionnalités de Devolutions Gateway.</String>
                 <String Id="VendorFullName">Devolutions Inc.</String>