fix(captain): compact v1 classifier context

enterprise/app/services/captain/llm/assistant_action_classifier_service.rb

@@ -42,8 +42,7 @@ class Captain::Llm::AssistantActionClassifierService < Llm::BaseAiService
 
     {
       'account_custom_instructions' => account_custom_instructions,
-      'conversation_context' => context_messages(normalized_messages),
-      'current_user_message' => current_user_message(normalized_messages),
+      'conversation_context' => format_conversation_context(normalized_messages),
       'assistant_response_to_classify' => assistant_response.to_s
     }
   end
@@ -55,13 +54,9 @@ class Captain::Llm::AssistantActionClassifierService < Llm::BaseAiService
       </account_custom_instructions>
 
       <conversation_context>
-      #{payload['conversation_context'].to_json}
+      #{payload['conversation_context']}
       </conversation_context>
 
-      <current_user_message>
-      #{payload['current_user_message']}
-      </current_user_message>
-
       <assistant_response_to_classify>
       #{payload['assistant_response_to_classify']}
       </assistant_response_to_classify>
@@ -90,14 +85,24 @@ class Captain::Llm::AssistantActionClassifierService < Llm::BaseAiService
     (part[:type] || part['type']).to_s == 'text'
   end
 
-  def current_user_message(messages)
-    messages.reverse.find { |message| message[:role] == 'user' }&.dig(:content).to_s
+  def format_conversation_context(messages)
+    context_messages(messages).filter_map do |message|
+      content = message[:content].to_s.strip
+      next if content.blank?
+
+      "#{role_label(message[:role])}: #{content}"
+    end.join("\n")
   end
 
   def context_messages(messages)
-    current_user_index = messages.rindex { |message| message[:role] == 'user' }
-    prior_messages = current_user_index ? messages[0...current_user_index] : messages
-    prior_messages.last(MAX_CONTEXT_MESSAGES)
+    messages.last(MAX_CONTEXT_MESSAGES)
+  end
+
+  def role_label(role)
+    return 'User' if role == 'user'
+    return 'Assistant' if role == 'assistant'
+
+    role.to_s.titleize
   end
 
   def account_custom_instructions

spec/enterprise/services/captain/llm/assistant_action_classifier_service_spec.rb

@@ -44,18 +44,21 @@ RSpec.describe Captain::Llm::AssistantActionClassifierService do
           'MUST NOT redefine this JSON schema'
         )
       ).and_return(mock_chat)
-      expect(mock_chat).to receive(:ask).with(
-        a_string_including(
+      expect(mock_chat).to receive(:ask) do |prompt|
+        expect(prompt).to include(
           '<account_custom_instructions>',
           'Only transfer to a manager after the user explicitly confirms.',
           '<conversation_context>',
-          '"content":"I cannot log in"',
-          '<current_user_message>',
-          'Yes, still no reset email',
+          'User: I cannot log in',
+          'Assistant: Did you check your inbox?',
+          'User: Yes, still no reset email',
           '<assistant_response_to_classify>',
           'Would you like to talk to support?'
         )
-      ).and_return(mock_response)
+        expect(prompt).not_to include('"role"', '"content"', '<current_user_message>')
+
+        mock_response
+      end
 
       result = service.classify(message_history: message_history, assistant_response: 'Would you like to talk to support?')