feat(smtp): allow separate auth username and From: address (Brevo sup…

[pulkitpareek18]

…port)

The "Gmail" provider path is really a generic SMTP transport — Brevo, Mailgun and Postmark all land here. But the single config.user field was used both as the SMTP login AND the visible From: address, so relays that issue a synthetic SMTP username (e.g. 9abc12@smtp-brevo.com with verified sender hello@thefoundersweb.com) couldn't send: every message either failed auth or was bounced for an unverified From:.

Add an optional fromEmail to the gmail/SMTP config. When present and non-blank it becomes the From: (and Reply-To default); when absent the behaviour is unchanged so every existing Gmail account keeps working.

• GmailProvider: new optional fromEmail; fromAddress resolved from fromEmail?.trim() || user; expose getFromAddress() + close() for tests so the connection pool releases cleanly.
• providerFactory: pass fromEmail through (not sensitive, no encryption).
• Settings UI: split the Gmail form into "Auth Email / SMTP Username" and optional "Sender Email", with helper text calling out Brevo. Account list now shows the sender address and, when different, the auth identity on a secondary line. Edit form gains the same field.
• New unit tests (gmailProvider.test.ts) pin the resolution rules: default → user, override → fromEmail, fromName wraps either, blank/ whitespace fromEmail treated as absent.

Server: tsc clean, 31/31 jest pass. Client: tsc clean, vite build clean.