feat: add OpenSkill and Glicko2 rating models to schema

prisma/schema.prisma

@@ -30,6 +30,9 @@ model Player {
   teamsAsPlayer1    Team[]             @relation("TeamPlayer1")
   teamsAsPlayer2    Team[]             @relation("TeamPlayer2")
   user              User?
+  eloRating         EloRating?
+  glicko2Rating     Glicko2Rating?
+  openSkillRating   OpenSkillRating?
 
   @@map("players")
 }
@@ -276,3 +279,55 @@ model Verification {
   @@index([identifier])
   @@map("verification")
 }
+
+model EloRating {
+  id          Int      @id @default(autoincrement())
+  playerId    Int      @unique
+  rating      Int      @default(1000)
+  volatility  Float    @default(0) // Optional: for advanced Elo variants
+  gamesPlayed Int      @default(0)
+  wins        Int      @default(0)
+  losses      Int      @default(0)
+  draws       Int      @default(0)
+  lastUpdated DateTime @default(now())
+  createdAt   DateTime @default(now())
+  updatedAt   DateTime @updatedAt
+  player      Player   @relation(fields: [playerId], references: [id], onDelete: Cascade)
+
+  @@map("elo_ratings")
+}
+
+model Glicko2Rating {
+  id          Int      @id @default(autoincrement())
+  playerId    Int      @unique
+  rating      Float    @default(1500.0) // mu
+  deviation   Float    @default(350.0) // phi
+  volatility  Float    @default(0.05) // sigma
+  gamesPlayed Int      @default(0)
+  wins        Int      @default(0)
+  losses      Int      @default(0)
+  draws       Int      @default(0)
+  lastUpdated DateTime @default(now())
+  createdAt   DateTime @default(now())
+  updatedAt   DateTime @updatedAt
+  player      Player   @relation(fields: [playerId], references: [id], onDelete: Cascade)
+
+  @@map("glicko2_ratings")
+}
+
+model OpenSkillRating {
+  id          Int      @id @default(autoincrement())
+  playerId    Int      @unique
+  rating      Float    @default(25.0) // mu
+  deviation   Float    @default(8.33) // sigma (std dev)
+  gamesPlayed Int      @default(0)
+  wins        Int      @default(0)
+  losses      Int      @default(0)
+  draws       Int      @default(0)
+  lastUpdated DateTime @default(now())
+  createdAt   DateTime @default(now())
+  updatedAt   DateTime @updatedAt
+  player      Player   @relation(fields: [playerId], references: [id], onDelete: Cascade)
+
+  @@map("open_skill_ratings")
+}