Refactor Study Desk application structure

prisma/schema.prisma

@@ -99,6 +99,8 @@ model StudyProgress {
   orderJson       String // JSON array of card/question ids
   answersJson     String? // in-progress quiz answers
   cardResultsJson String? // per-card grades for decks
+  sessionId       String   @default("legacy")
+  revision        Int      @default(0)
   updatedAt       DateTime @updatedAt
 
   deck    Deck?    @relation(fields: [deckId], references: [id], onDelete: Cascade)
@@ -109,13 +111,14 @@ model StudyProgress {
 }
 
 model QuizAttempt {
-  id              String   @id @default(uuid())
-  quizSetId       String
-  score           Float
-  maxScore        Int
-  answersJson     String
-  isPartialRetake Boolean  @default(false)
-  completedAt     DateTime @default(now())
+  id                 String   @id @default(uuid())
+  quizSetId          String
+  score              Float
+  maxScore           Int
+  answersJson        String
+  reviewSnapshotJson String?
+  isPartialRetake    Boolean  @default(false)
+  completedAt        DateTime @default(now())
 
   quizSet QuizSet @relation(fields: [quizSetId], references: [id], onDelete: Cascade)
 }