fix(captain-memory): ContradictionChecker exact-match parsing + rescue wrap + LLM failure test

enterprise/app/services/captain/contact_memories/contradiction_checker_service.rb

@@ -13,6 +13,8 @@ class Captain::ContactMemories::ContradictionCheckerService
     candidates.each do |candidate|
       candidate.supersede_by!(@memory) if contradicts?(candidate, @memory)
     end
+  rescue StandardError => e
+    Rails.logger.error("[ContradictionChecker] call failed: #{e.class}: #{e.message} (memory_id=#{@memory&.id})")
   end
 
   private
@@ -26,23 +28,31 @@ class Captain::ContactMemories::ContradictionCheckerService
       .where.not(embedding: nil)
       .nearest_neighbors(:embedding, @memory.embedding, distance: 'cosine')
       .first(MAX_CANDIDATES)
-      .select { |c| cosine_distance(c) < DISTANCE_THRESHOLD }
-  end
-
-  def cosine_distance(other)
-    other.neighbor_distance
+      .select { |c| c.neighbor_distance < DISTANCE_THRESHOLD }
   end
 
   def contradicts?(fact_a, fact_b)
-    response = RubyLLM.chat(model: CHECK_MODEL).with_temperature(0).ask(<<~PROMPT).content.to_s.downcase
+    answer = query_llm_for_contradiction(fact_a, fact_b)
+    answer == 'sim'
+  rescue StandardError => e
+    Rails.logger.warn("[ContradictionChecker] #{e.class}: #{e.message}")
+    false
+  end
+
+  def query_llm_for_contradiction(fact_a, fact_b)
+    response = RubyLLM.chat(model: CHECK_MODEL).with_temperature(0).ask(contradiction_prompt(fact_a, fact_b)).content.to_s
+    # Extract the first meaningful word. Expected "sim" or "nao" (or "não").
+    first_word = response.strip.downcase.gsub(/[^a-zãáéíóúç]/, ' ').split.first.to_s
+    # Normalize "não" → "nao" for ASCII comparison
+    first_word.tr('ãáéíóúç', 'aaeiouc')
+  end
+
+  def contradiction_prompt(fact_a, fact_b)
+    <<~PROMPT
       Estes 2 fatos sobre o mesmo cliente se contradizem?
       Fato A: "#{fact_a.content}"
       Fato B: "#{fact_b.content}"
       Responda apenas "sim" ou "nao".
     PROMPT
-    response.include?('sim')
-  rescue StandardError => e
-    Rails.logger.warn("[ContradictionChecker] #{e.class}: #{e.message}")
-    false
   end
 end

spec/enterprise/services/captain/contact_memories/contradiction_checker_service_spec.rb

@@ -57,5 +57,20 @@ RSpec.describe Captain::ContactMemories::ContradictionCheckerService do
       expect { described_class.new(memory: embeddingless).call }.not_to raise_error
       expect(old_fact.reload.superseded_by_id).to be_nil
     end
+
+    context 'when LLM raises during contradiction check' do
+      it 'does not supersede when LLM raises' do
+        old_fact
+        chat_double = instance_double(RubyLLM::Chat)
+        allow(chat_double).to receive(:with_temperature).and_return(chat_double)
+        allow(chat_double).to receive(:ask).and_raise(StandardError, 'LLM down')
+        allow(RubyLLM).to receive(:chat).and_return(chat_double)
+
+        # Exercise the real rescue path inside contradicts? (no stub here)
+        real_service = described_class.new(memory: new_fact)
+        expect { real_service.call }.not_to raise_error
+        expect(old_fact.reload.superseded_by_id).to be_nil
+      end
+    end
   end
 end