feat: cap automated reminders before resend (#3016)

Stop sending automated reminders after a configurable threshold
(default 5) and reset the count on manual resend.

packages/prisma/migrations/20260622120000_add_recipient_reminder_count/migration.sql

@@ -0,0 +1,2 @@
+-- AlterTable
+ALTER TABLE "Recipient" ADD COLUMN     "reminderCount" INTEGER NOT NULL DEFAULT 0;

packages/prisma/schema.prisma

@@ -642,6 +642,7 @@ model Recipient {
   signedAt             DateTime?
   lastReminderSentAt   DateTime?
   nextReminderAt       DateTime?
+  reminderCount        Int           @default(0)
   authOptions          Json? /// [RecipientAuthOptions] @zod.custom.use(ZRecipientAuthOptionsSchema)
   signingOrder         Int? /// @zod.number.describe("The order in which the recipient should sign the document. Only works if the document is set to sequential signing.")
   rejectionReason      String?