feat(auth): add password reset flow with OTP

- Add password-reset Prisma schema for OTP tracking
- Add API contract schemas (start, verify, resend)
- Add password-reset service with OTP validation and email sending
- Add frontend reset-password page with 2-step flow
- Add InputOTP component usage for OTP input
- Add link to reset-password in login page
- Remove link to About in login
- Center and resize login/reset password forms

apps/backend/prisma/password-reset.prisma

@@ -0,0 +1,16 @@
+model PasswordResetRequest {
+  id            String    @id @db.Uuid
+  email         String
+  otpHash       String    @map("otp_hash")
+  otpExpiresAt  DateTime  @map("otp_expires_at")
+  otpAttempts   Int       @default(0) @map("otp_attempts")
+  otpLastSentAt DateTime  @map("otp_last_sent_at")
+  otpResendCount Int      @default(0) @map("otp_resend_count")
+  usedAt        DateTime? @map("used_at")
+  createdAt     DateTime  @default(now()) @map("created_at")
+  updatedAt     DateTime  @updatedAt @map("updated_at")
+
+  @@index([email])
+  @@index([otpExpiresAt])
+  @@map("password_reset_requests")
+}