feat: add distributed architecture with sharding and coordination

- Wire up distributed components (Coordinator, ShardManager, CacheSync)
- Implement automatic sharding for S3 storage (256 shards)
- Add read/write separation for operational modes
- Zero-config automatic detection for distributed mode
- Add mutex implementation for thread safety
- Fix metadata filtering in find operations
- Fix neural API vector similarity calculations
- Improve batch operations performance
- Add Bluesky distributed setup example

BREAKING CHANGE: None - backward compatible

.gitignore

@@ -62,6 +62,11 @@ TODO_PRIVATE.md
 
 # Strategy and planning documents (private)
 .strategy/
+PRODUCTION_*.md
+DISTRIBUTED_*.md
+*_ASSESSMENT.md
+*_ANALYSIS.md
+*_TRUTH*.md
 
 # Models (downloaded at runtime)
 models/