-- AlterTable: Add soft delete column to Task
ALTER TABLE "Task" ADD COLUMN "deletedAt" TIMESTAMP(3);

-- CreateIndex: Index for efficient filtering of non-deleted tasks
CREATE INDEX "Task_userId_deletedAt_idx" ON "Task"("userId", "deletedAt");

-- AlterTable: Change onDelete behavior for somedayList relation
-- Drop old foreign key and add new one with SET NULL
ALTER TABLE "Task" DROP CONSTRAINT IF EXISTS "Task_somedayListId_fkey";
ALTER TABLE "Task" ADD CONSTRAINT "Task_somedayListId_fkey" FOREIGN KEY ("somedayListId") REFERENCES "SomedayList"("id") ON DELETE SET NULL ON UPDATE CASCADE;