Redesign login/register with Mento branding and email/mobile OTP.

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/api/prisma/migrations/20260905010000_auth_mobile_otp/migration.sql

@@ -0,0 +1,33 @@
+-- AlterTable
+ALTER TABLE "User" ADD COLUMN IF NOT EXISTS "mobile" TEXT;
+ALTER TABLE "User" ADD COLUMN IF NOT EXISTS "emailVerifiedAt" TIMESTAMP(3);
+ALTER TABLE "User" ADD COLUMN IF NOT EXISTS "mobileVerifiedAt" TIMESTAMP(3);
+
+-- CreateIndex
+CREATE UNIQUE INDEX IF NOT EXISTS "User_mobile_key" ON "User"("mobile");
+CREATE INDEX IF NOT EXISTS "User_email_idx" ON "User"("email");
+
+-- CreateTable
+CREATE TABLE IF NOT EXISTS "AuthChallenge" (
+    "id" TEXT NOT NULL,
+    "kind" TEXT NOT NULL,
+    "channel" TEXT,
+    "email" TEXT,
+    "mobile" TEXT,
+    "passwordHash" TEXT,
+    "payload" JSONB NOT NULL DEFAULT '{}',
+    "emailCode" TEXT,
+    "mobileCode" TEXT,
+    "emailVerified" BOOLEAN NOT NULL DEFAULT false,
+    "mobileVerified" BOOLEAN NOT NULL DEFAULT false,
+    "expiresAt" TIMESTAMP(3) NOT NULL,
+    "consumedAt" TIMESTAMP(3),
+    "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+
+    CONSTRAINT "AuthChallenge_pkey" PRIMARY KEY ("id")
+);
+
+CREATE INDEX IF NOT EXISTS "AuthChallenge_kind_createdAt_idx" ON "AuthChallenge"("kind", "createdAt");
+CREATE INDEX IF NOT EXISTS "AuthChallenge_expiresAt_idx" ON "AuthChallenge"("expiresAt");
+CREATE INDEX IF NOT EXISTS "AuthChallenge_email_idx" ON "AuthChallenge"("email");
+CREATE INDEX IF NOT EXISTS "AuthChallenge_mobile_idx" ON "AuthChallenge"("mobile");