feat: remove email rate limit configuration from environment and database schema

backend/src/db/migrate.ts

@@ -58,7 +58,6 @@ async function main() {
       smtp_pass_encrypted text,
       smtp_from text,
       smtp_secure integer NOT NULL DEFAULT 0,
-      emails_per_day integer NOT NULL DEFAULT 3,
       email_enabled integer NOT NULL DEFAULT 0,
       notification_email text,
       reminder_days_before integer NOT NULL DEFAULT 7,

backend/src/db/schema.ts

@@ -51,7 +51,6 @@ export const settings = sqliteTable("settings", {
   smtpPassEncrypted: text("smtp_pass_encrypted"),
   smtpFrom: text("smtp_from"),
   smtpSecure: integer("smtp_secure", { mode: "boolean" }).notNull().default(false),
-  emailsPerDay: integer("emails_per_day").notNull().default(3),
   // Email notification settings
   emailEnabled: integer("email_enabled", { mode: "boolean" }).notNull().default(false),
   notificationEmail: text("notification_email"),