Revert "fix: try fixing OTP ids again =/"

This reverts commit 1a987fe75f.

lib/auth.ts

@@ -43,7 +43,6 @@ export const auth = betterAuth({
   },
   advanced: {
     cookiePrefix: "taxhacker",
-    generateId: true,
   },
   plugins: [
     emailOTP({

prisma/migrations/20260125140000_verification_identifier_unique/migration.sql

@@ -1,9 +0,0 @@
--- Delete any duplicate verification rows (keep the most recent per identifier) before adding unique constraint.
--- Verification rows are short-lived (e.g. OTP); duplicates can occur if create succeeded but delete failed.
-DELETE FROM "verification" a
-USING "verification" b
-WHERE a."identifier" = b."identifier"
-  AND a."created_at" < b."created_at";
-
--- CreateIndex
-CREATE UNIQUE INDEX "verification_identifier_key" ON "verification"("identifier");

prisma/schema.prisma

@@ -80,7 +80,7 @@ model Account {
 
 model Verification {
   id         String   @id @default(uuid()) @db.Uuid
-  identifier String   @unique
+  identifier String
   value      String
   expiresAt  DateTime @map("expires_at")
   createdAt  DateTime @default(now()) @map("created_at")