feat: ToolChoice + ToolNames pro Chain in DB speichern

- ChainRecord: neue Felder ToolChoice (auto/any) und ToolNames (JSON-Array)
- DatabaseService: Migration tool_choice + tool_names Spalten, INSERT erweitert
- ChatEndpoint: berechnet Tools vor Chain-Erstellung, speichert Werte mit
- ToolService: execute-Timeout Beschreibung korrigiert (30s → 180s)

Endpoints/ChatEndpoint.cs

@@ -85,13 +85,31 @@ public static class ChatEndpoint
 
         var chainId = Guid.NewGuid().ToString("N");
 
+        var workspace = session.Workspace;
+        var toolChoice = agent.ToolChoice ?? "any";
+        var hasWorkspace = !string.IsNullOrEmpty(workspace);
+        var includeMemory = agent.UseMemory && !string.IsNullOrEmpty(agent.AgentId);
+        var toolDefs = (hasWorkspace || includeMemory)
+            ? toolService.GetToolDefinitions(includeFileTools: hasWorkspace, includeMemory: includeMemory)
+            : Array.Empty<object>();
+        var toolNames = toolDefs.Length > 0
+            ? JsonSerializer.Serialize(toolDefs.Select(td =>
+            {
+                var json = JsonSerializer.Serialize(td);
+                var el = JsonSerializer.Deserialize<JsonElement>(json);
+                return el.GetProperty("name").GetString();
+            }).ToArray())
+            : null;
+
         await db.CreateChain(new ChainRecord
         {
             ChainId = chainId,
             SessionId = sessionId,
             AgentId = agent.AgentId,
             Model = modelId,
-            SystemPrompt = systemPromptText
+            SystemPrompt = systemPromptText,
+            ToolChoice = (hasWorkspace || includeMemory) ? toolChoice : null,
+            ToolNames = toolNames
         });
 
         // Session-Timestamp aktualisieren
@@ -150,12 +168,10 @@ public static class ChatEndpoint
             ? new List<object>()
             : new List<object> { new { type = "text", text = systemPromptText } };
 
-        var workspace = session.Workspace;
         if (!string.IsNullOrEmpty(workspace))
             Directory.CreateDirectory(workspace);
 
         var maxIterations = config.GetValue<int>("MaxIterations", 100);
-        var toolChoice = agent.ToolChoice ?? "any";
 
         var anthropic = new AnthropicService(httpFactory, token, toolService, db, memoryService);
         streamingTracker.Start(sessionId, chainId);