Refactor blob storage to use UUID primary keys and implement streaming chunking

- Changed blob table to use ID (UUID) as primary key instead of hash
- Blob records are now created at packing start, enabling immediate chunk associations
- Implemented streaming chunking to process large files without memory exhaustion
- Fixed blob manifest generation to include all referenced blobs
- Updated all foreign key references from blob_hash to blob_id
- Added progress reporting and improved error handling
- Enforced encryption requirement for all blob packing
- Updated tests to use test encryption keys
- Added Cyrillic transliteration to README

internal/blob/errors.go

@@ -0,0 +1,6 @@
+package blob
+
+import "errors"
+
+// ErrBlobSizeLimitExceeded is returned when adding a chunk would exceed the blob size limit
+var ErrBlobSizeLimitExceeded = errors.New("adding chunk would exceed blob size limit")