feat: Add Step 13 - Search System with Apache Solr and Data Persistence

- Implemented search service with Apache Solr instead of Elasticsearch
- Added full-text search, faceted search, and autocomplete capabilities
- Created data indexer for synchronizing data from MongoDB/Kafka to Solr
- Configured external volume mounts for all data services:
  - MongoDB, Redis, Kafka, Zookeeper, MinIO, Solr
  - All data now persists in ./data/ directory
- Added comprehensive search API endpoints
- Created documentation for data persistence and backup strategies

🤖 Generated with [Claude Code](https://claude.ai/code)

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

.gitignore

@@ -64,4 +64,4 @@ temp/
 *.pem
 *.key
 *.crt
-secrets/
+secrets/data/