feat(bot): enhance topic processor logging for diagnosis

Added comprehensive logging to topic-processor.ts to capture API errors, parsing failures, and silent decisions. Also added result logging to purchase and payment ingestion handlers to trace the processor's output.

apps/bot/src/purchase-topic-ingestion.ts

@@ -2476,6 +2476,11 @@ export function registerConfiguredPurchaseTopicIngestion(
           engagementAssessment: conversationContext.engagement
         })
 
+        options.logger?.info(
+          { event: 'purchase.topic_processor_result', result: processorResult },
+          'Topic processor finished'
+        )
+
         // Handle processor failure - fun "bot sleeps" message only if explicitly mentioned
         if (!processorResult) {
           if (conversationContext.explicitMention) {