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/database/snapshots_test.go

@@ -30,7 +30,8 @@ func TestSnapshotRepository(t *testing.T) {
 		ID:               "2024-01-01T12:00:00Z",
 		Hostname:         "test-host",
 		VaultikVersion:   "1.0.0",
-		CreatedTS:        time.Now().Truncate(time.Second),
+		StartedAt:        time.Now().Truncate(time.Second),
+		CompletedAt:      nil,
 		FileCount:        100,
 		ChunkCount:       500,
 		BlobCount:        10,
@@ -99,7 +100,8 @@ func TestSnapshotRepository(t *testing.T) {
 			ID:             fmt.Sprintf("2024-01-0%dT12:00:00Z", i),
 			Hostname:       "test-host",
 			VaultikVersion: "1.0.0",
-			CreatedTS:      time.Now().Add(time.Duration(i) * time.Hour).Truncate(time.Second),
+			StartedAt:      time.Now().Add(time.Duration(i) * time.Hour).Truncate(time.Second),
+			CompletedAt:    nil,
 			FileCount:      int64(100 * i),
 			ChunkCount:     int64(500 * i),
 			BlobCount:      int64(10 * i),
@@ -121,7 +123,7 @@ func TestSnapshotRepository(t *testing.T) {
 
 	// Verify order (most recent first)
 	for i := 0; i < len(recent)-1; i++ {
-		if recent[i].CreatedTS.Before(recent[i+1].CreatedTS) {
+		if recent[i].StartedAt.Before(recent[i+1].StartedAt) {
 			t.Error("snapshots not in descending order")
 		}
 	}
@@ -162,7 +164,8 @@ func TestSnapshotRepositoryDuplicate(t *testing.T) {
 		ID:             "2024-01-01T12:00:00Z",
 		Hostname:       "test-host",
 		VaultikVersion: "1.0.0",
-		CreatedTS:      time.Now().Truncate(time.Second),
+		StartedAt:      time.Now().Truncate(time.Second),
+		CompletedAt:    nil,
 		FileCount:      100,
 		ChunkCount:     500,
 		BlobCount:      10,