feat(migration): add migration for SpecialSong model

prisma/migrations/20251123012308_add_special_song_model/migration.sql

@@ -0,0 +1,21 @@
+-- CreateTable
+CREATE TABLE "SpecialSong" (
+    "id" INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
+    "specialId" INTEGER NOT NULL,
+    "songId" INTEGER NOT NULL,
+    "startTime" INTEGER NOT NULL DEFAULT 0,
+    "order" INTEGER,
+    CONSTRAINT "SpecialSong_specialId_fkey" FOREIGN KEY ("specialId") REFERENCES "Special" ("id") ON DELETE CASCADE ON UPDATE CASCADE,
+    CONSTRAINT "SpecialSong_songId_fkey" FOREIGN KEY ("songId") REFERENCES "Song" ("id") ON DELETE CASCADE ON UPDATE CASCADE
+);
+
+-- Migrate data from _SongToSpecial to SpecialSong
+INSERT INTO "SpecialSong" ("specialId", "songId", "startTime")
+SELECT "B" as "specialId", "A" as "songId", 0 as "startTime"
+FROM "_SongToSpecial";
+
+-- DropTable
+DROP TABLE "_SongToSpecial";
+
+-- CreateIndex
+CREATE UNIQUE INDEX "SpecialSong_specialId_songId_key" ON "SpecialSong"("specialId", "songId");