route OTP email delivery through SMTP relay settings

Make rms.auth.otp_email use SMTP transport with the same host/port/auth/tls settings model as smtp relay, with outbox fallback when SMTP is unavailable. Extend OTP plugin settings schema to expose standard SMTP parameters in plugin config.

plugins/rms.auth.otp_email/manifest.json

@@ -12,7 +12,14 @@
   "settingsSchema": {
     "type": "object",
     "properties": {
-      "from": { "type": "string" }
+      "host": { "type": "string" },
+      "port": { "type": "integer", "minimum": 1, "maximum": 65535 },
+      "secure": { "type": "boolean" },
+      "authUser": { "type": "string" },
+      "authPass": { "type": "string" },
+      "from": { "type": "string" },
+      "replyTo": { "type": "string" },
+      "allowInvalidCert": { "type": "boolean" }
     },
     "additionalProperties": false
   },