Add Ollama diagnostic logging and broaden tool-call retry

Log model name, tool count, raw response preview, and parsed
tool_call count at INFO level. Broaden the retry nudge to trigger
whenever no tools are called on the first attempt, not just when
code is detected.

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

src/Purrse.Api/Services/ChatService.cs

@@ -227,8 +227,28 @@ public class ChatService : IChatService
             }
             else
             {
+                var rawContent = response?.Message?.Content ?? "I'm sorry, I couldn't process that request.";
+
+                // If the model responded without calling any tools on the first attempt,
+                // it likely fabricated data or generated code. Nudge it to use tools.
+                if (toolResults.Count == 0 && i == 0)
+                {
+                    _logger.LogWarning("Model responded without calling tools on first attempt, retrying with nudge");
+                    ollamaMessages.Add(new OllamaToolMessage
+                    {
+                        Role = "assistant",
+                        Content = rawContent
+                    });
+                    ollamaMessages.Add(new OllamaToolMessage
+                    {
+                        Role = "user",
+                        Content = "You did not use any tools. You MUST call the provided function tools to look up or modify my financial data. Do not make up data. Try again."
+                    });
+                    continue;
+                }
+
                 // No tool calls - save final assistant message
-                var content = StripCodeBlocks(response?.Message?.Content ?? "I'm sorry, I couldn't process that request.");
+                var content = StripCodeBlocks(rawContent);
                 assistantDbMessage = new ChatMessage
                 {
                     Id = Guid.NewGuid(),
@@ -417,13 +437,22 @@ public class ChatService : IChatService
         var json = JsonSerializer.Serialize(request, OllamaJsonOptions);
         var content = new StringContent(json, Encoding.UTF8, "application/json");
 
-        _logger.LogDebug("Sending chat request to Ollama: {Url}", $"{ollamaUrl}/api/chat");
+        _logger.LogInformation("Ollama request — model: {Model}, tools: {ToolCount}, messages: {MessageCount}",
+            request.Model, request.Tools?.Count ?? 0, request.Messages.Count);
 
         var response = await client.PostAsync($"{ollamaUrl}/api/chat", content);
         response.EnsureSuccessStatusCode();
 
         var responseBody = await response.Content.ReadAsStringAsync();
-        return JsonSerializer.Deserialize<OllamaToolChatResponse>(responseBody, OllamaJsonOptions);
+        _logger.LogInformation("Ollama response — length: {Length}, preview: {Preview}",
+            responseBody.Length, responseBody.Length > 500 ? responseBody[..500] : responseBody);
+
+        var parsed = JsonSerializer.Deserialize<OllamaToolChatResponse>(responseBody, OllamaJsonOptions);
+        _logger.LogInformation("Ollama parsed — tool_calls: {ToolCallCount}, content_length: {ContentLength}",
+            parsed?.Message?.ToolCalls?.Count ?? 0,
+            parsed?.Message?.Content?.Length ?? 0);
+
+        return parsed;
     }
 
     private async Task<(string toolResultType, object data, string summaryForLlm)> ExecuteToolAsync(Guid userId, OllamaToolCall toolCall)
@@ -1108,6 +1137,16 @@ public class ChatService : IChatService
         };
     }
 
+    // Detect responses that contain code blocks or common code patterns
+    private static bool LooksLikeCodeResponse(string content)
+    {
+        if (content.Contains("```")) return true;
+        if (content.Contains("import ") && content.Contains("(")) return true;
+        if (content.Contains("def ") && content.Contains("():")) return true;
+        if (content.Contains("print(") || content.Contains("console.log(")) return true;
+        return false;
+    }
+
     // Strip fenced code blocks that smaller models sometimes generate instead of using tools
     private static readonly Regex CodeBlockRegex = new(@"```[\s\S]*?```", RegexOptions.Compiled);
     private static string StripCodeBlocks(string content)