feat: CLI-Fallback für Sub-Agents (Preparer/Review/Finalizer) wenn kein API-Key zugewiesen

Statt Hard-Error "Kein API-Key zugewiesen" nutzen Sub-Agents jetzt
Claude CLI als Fallback. Preparer wird nur übersprungen wenn weder
Key noch CLI verfügbar sind.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Services/AnthropicService.Agents.cs

@@ -63,6 +63,13 @@ public partial class AnthropicService
             text = await _openAiService.ChatNonStreaming(subCtx, preparerMessages);
             iterations = 1;
         }
+        else if (string.IsNullOrEmpty(apiToken) && _cliService != null && _cliService.IsAvailable)
+        {
+            // Kein API-Key → CLI-Fallback
+            (text, iterations) = await RunSubAgentViaCli(
+                response, preparer, preparerMessages, chainId, sessionId,
+                "preparer", cancellationToken, cancellationToken);
+        }
         else
         {
             (text, iterations) = await RunAgentChat(
@@ -164,6 +171,13 @@ public partial class AnthropicService
             text = await _openAiService.ChatNonStreaming(subCtx, reviewMessages);
             iterations = 1;
         }
+        else if (string.IsNullOrEmpty(apiToken) && _cliService != null && _cliService.IsAvailable)
+        {
+            // Kein API-Key → CLI-Fallback
+            (text, iterations) = await RunSubAgentViaCli(
+                response, review, reviewMessages, chainId, sessionId,
+                "review", workCt, sseCt);
+        }
         else
         {
             (text, iterations) = await RunAgentChat(
@@ -228,6 +242,13 @@ public partial class AnthropicService
             text = await _openAiService.ChatNonStreaming(subCtx, finalizerMessages);
             iterations = 1;
         }
+        else if (string.IsNullOrEmpty(apiToken) && _cliService != null && _cliService.IsAvailable)
+        {
+            // Kein API-Key → CLI-Fallback
+            (text, iterations) = await RunSubAgentViaCli(
+                response, finalizer, finalizerMessages, chainId, sessionId,
+                "finalizer", workCt, sseCt);
+        }
         else
         {
             (text, iterations) = await RunAgentChat(
@@ -624,6 +645,88 @@ public partial class AnthropicService
             });
     }
 
+    /// <summary>
+    /// Führt einen Sub-Agent (Preparer/Review/Finalizer) über die Claude CLI aus.
+    /// Sammelt den gesamten Text und gibt ihn zurück. Wird als Fallback genutzt,
+    /// wenn kein API-Key vorhanden ist.
+    /// </summary>
+    private async Task<(string text, int iterations)> RunSubAgentViaCli(
+        HttpResponse response,
+        SubAgentContext sub,
+        List<object> historyMessages,
+        string chainId,
+        string sessionId,
+        string agentType,
+        CancellationToken workCt,
+        CancellationToken sseCt)
+    {
+        if (_cliService == null || !_cliService.IsAvailable)
+            return ("", 0);
+
+        // System-Prompt als Text extrahieren
+        var systemText = new StringBuilder();
+        if (sub.SystemPrompt != null)
+        {
+            foreach (var block in sub.SystemPrompt)
+            {
+                var json = JsonSerializer.Serialize(block);
+                var el = JsonSerializer.Deserialize<JsonElement>(json);
+                if (el.TryGetProperty("text", out var t))
+                    systemText.AppendLine(t.GetString());
+            }
+        }
+
+        // Letzte User-Message als Prompt extrahieren
+        var prompt = ExtractLastUserText(historyMessages) ?? "";
+
+        // Konversations-History als Kontext
+        var historyContext = BuildHistoryContext(historyMessages);
+        if (!string.IsNullOrEmpty(historyContext))
+            prompt = $"<conversation_history>\n{historyContext}\n</conversation_history>\n\n<current_request>\n{prompt}\n</current_request>";
+
+        var fullText = new StringBuilder();
+
+        var result = await _cliService.ChatStreamingAsync(
+            prompt,
+            async evt =>
+            {
+                switch (evt.Type)
+                {
+                    case CliEventType.TextDelta:
+                        fullText.Append(evt.Text);
+                        await SseHelper.TryWriteSse(response, $"{agentType}_text",
+                            new { text = evt.Text, agentName = sub.Agent?.Name ?? agentType }, sseCt);
+                        break;
+                    case CliEventType.ToolResult:
+                        await SseHelper.TryWriteSse(response, $"{agentType}_tool",
+                            new { name = evt.ToolName, result = evt.ToolResultContent, isError = evt.ToolResultIsError, agentName = sub.Agent?.Name ?? agentType }, sseCt);
+                        break;
+                }
+            },
+            modelId: sub.ModelId,
+            systemPrompt: systemText.ToString(),
+            workspace: sub.Workspace,
+            hasWorkspace: !string.IsNullOrEmpty(sub.Workspace),
+            cancellationToken: workCt
+        );
+
+        // Text in DB speichern
+        if (fullText.Length > 0)
+        {
+            await _db.SaveMessage(new MessageRecord
+            {
+                ChainId = chainId,
+                Iteration = 0,
+                Role = "assistant",
+                Type = "text",
+                Content = fullText.ToString(),
+                Tag = agentType
+            });
+        }
+
+        return (fullText.ToString(), 1);
+    }
+
     /// <summary>
     /// Non-Streaming Chat für Telegram. Gibt den finalen Antworttext zurück.
     /// Wrapper um RunNonStreamingToolLoop mit Chain-Management und Embedding-Enqueue.