EMAIL_TLS_REJECT_UNAUTHORIZED=0 does not disable SMTP TLS certificate validation

[matt-rgx]

Describe the bug
EMAIL_TLS_REJECT_UNAUTHORIZED does not work as documented for SMTP magic-link login.

According to the docs and the PR that introduced it, setting EMAIL_TLS_REJECT_UNAUTHORIZED=0 should disable TLS
certificate validation for SMTP relays using self-signed certificates (for example ProtonMail Bridge).

In practice, SplitPro still fails with self-signed certificate, because the env var is parsed with
Boolean(process.env.EMAIL_TLS_REJECT_UNAUTHORIZED), which evaluates "0" and "false" to true.

So it appears impossible to set tls.rejectUnauthorized to false via environment variables.

To Reproduce
Steps to reproduce the behavior:

1. Deploy SplitPro with SMTP login enabled
2. Use an SMTP relay with a self-signed certificate (for example ProtonMail Bridge)
3. Set EMAIL_TLS_REJECT_UNAUTHORIZED=0
4. Try to log in with the email magic link
5. See the login email fail to send with self-signed certificate

Expected behavior
When EMAIL_TLS_REJECT_UNAUTHORIZED=0 is set, SplitPro should configure Nodemailer with tls.rejectUnauthorized = false and successfully send the magic-link email through SMTP relays using self-signed certificates.

Screenshots
Not applicable.

App version
2.1.1 (NEXT_PUBLIC_APP_VERSION=2.1.1)

Desktop (please complete the following information):

• OS: Debian 13 server on Docker host
• Browser: Firefox
• Version: latest

Smartphone (please complete the following information):
Not tested

Additional context
The relevant code introduced in PR #611 appears to be:

EMAIL_TLS_REJECT_UNAUTHORIZED: process.env.EMAIL_TLS_REJECT_UNAUTHORIZED
  ? Boolean(process.env.EMAIL_TLS_REJECT_UNAUTHORIZED)
  : true

This causes:

• EMAIL_TLS_REJECT_UNAUTHORIZED=0 -> Boolean("0") -> true
• EMAIL_TLS_REJECT_UNAUTHORIZED=false -> Boolean("false") -> true

So the variable cannot effectively disable TLS verification.

In our case, the runtime logs still show:

Error sending email [Error: self-signed certificate] { code: 'ESOCKET', command: 'CONN' }
[next-auth][error][SIGNIN_EMAIL_ERROR]

The documentation says:

• EMAIL_TLS_REJECT_UNAUTHORIZED: Validates TLS certificates by default. Set it to 0 if you have a relay that needs it

So the docs are correct, but the boolean parsing seems broken.