fix: Chat via agentId statt sessionKey + reply aus details parsen

- SendChatMessageAsync: sessions_send nutzt agentId (nicht sessionKey)
- Reply parsen aus result.details.reply (sessions_send Antwort-Struktur)
- ChatRequest.Model: SessionKey → AgentId
- Controller default: 'iris' → Agent-ID (nicht Session-Key)

backend/Controllers/DashboardController.cs

@@ -95,11 +95,11 @@ public class DashboardController(OpenClawGatewayClient gateway, ILogger<Dashboar
 
         try
         {
-            var sessionKey = string.IsNullOrWhiteSpace(request.SessionKey)
+            var agentId = string.IsNullOrWhiteSpace(request.AgentId)
                 ? "iris"
-                : request.SessionKey.Trim();
+                : request.AgentId.Trim();
 
-            return await gateway.SendChatMessageAsync(sessionKey, request.Message.Trim());
+            return await gateway.SendChatMessageAsync(agentId, request.Message.Trim());
         }
         catch (Exception ex)
         {

backend/Models/Dashboard.cs

@@ -17,7 +17,7 @@ public sealed record MessageEntry(
 
 public sealed record ChatRequest(
     string Message,
-    string? SessionKey
+    string? AgentId
 );
 
 public sealed record ChatResponse(

backend/Services/OpenClawGatewayClient.cs

@@ -173,18 +173,21 @@ public sealed class OpenClawGatewayClient(HttpClient httpClient, IConfiguration
         }
     }
 
-    public async Task<ChatResponse> SendChatMessageAsync(string sessionKey, string message)
+    public async Task<ChatResponse> SendChatMessageAsync(string agentId, string message)
     {
         try
         {
-            var result = await InvokeToolAsync("sessions_send", new { sessionKey, message });
+            var result = await InvokeToolAsync("sessions_send", new { agentId, message });
             if (result is null) return new ChatResponse(false, null, "Gateway nicht erreichbar");
 
-            var ok = result["ok"]?.GetValue<bool>() ?? false;
-            var reply = result["reply"]?.GetValue<string>()
+            // sessions_send reply is in details.reply or content[0].text
+            var details = result["details"];
+            var ok = (details?["status"]?.GetValue<string>() ?? result["status"]?.GetValue<string>()) == "ok";
+            var reply = details?["reply"]?.GetValue<string>()
+                ?? result["reply"]?.GetValue<string>()
                 ?? result["response"]?.GetValue<string>()
                 ?? result["content"]?[0]?["text"]?.GetValue<string>();
-            var error = result["error"]?.GetValue<string>();
+            var error = details?["error"]?.GetValue<string>() ?? result["error"]?.GetValue<string>();
 
             return new ChatResponse(ok, reply, error);
         }