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/migrations/20260412231443_add_password_reset_requests/migration.sql

@@ -0,0 +1,21 @@
+-- CreateTable
+CREATE TABLE "password_reset_requests" (
+    "id" UUID NOT NULL,
+    "email" TEXT NOT NULL,
+    "otp_hash" TEXT NOT NULL,
+    "otp_expires_at" TIMESTAMP(3) NOT NULL,
+    "otp_attempts" INTEGER NOT NULL DEFAULT 0,
+    "otp_last_sent_at" TIMESTAMP(3) NOT NULL,
+    "otp_resend_count" INTEGER NOT NULL DEFAULT 0,
+    "used_at" TIMESTAMP(3),
+    "created_at" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "updated_at" TIMESTAMP(3) NOT NULL,
+
+    CONSTRAINT "password_reset_requests_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateIndex
+CREATE INDEX "password_reset_requests_email_idx" ON "password_reset_requests"("email");
+
+-- CreateIndex
+CREATE INDEX "password_reset_requests_otp_expires_at_idx" ON "password_reset_requests"("otp_expires_at");