feat(mail/delivery): add error-count based blocking to rate limiter; improve test SMTP server port selection; add tsbuild scripts and devDependency; remove stale backup file

ts/00_commitinfo_data.ts

@@ -0,0 +1,8 @@
+/**
+ * autocreated commitinfo by @push.rocks/commitinfo
+ */
+export const commitinfo = {
+  name: '@serve.zone/mailer',
+  version: '1.3.0',
+  description: 'Enterprise mail server with SMTP, HTTP API, and DNS management - built for serve.zone infrastructure'
+}