Closes#3600. Previously the From header on test emails and notifications
showed only the raw email address. Adds an optional "Sender name" field
so emails appear from a friendly name like "Checkmate notifications"
<user@example.org>.
## Behaviour
- Field is optional. When empty/null/whitespace, the From header falls
back to the raw email address — identical to current behaviour, no
regression for existing installs.
- When set, the email service hands nodemailer { name, address } as the
message from field. Nodemailer handles RFC-5322 encoding (quotes,
commas, non-ASCII) so the display name is safe for any input.
- Unsetting works: clearing the input transforms the value to null in
the Zod parse step, and the settings repository already turns null
values into a $unset operation.
- Both client and server Zod schemas trim and empty-string-to-null,
preventing whitespace-only display names from being stored.
## Surfaces
- AppSettings schema, Settings type, EmailTransportConfig pick, server
Zod validation, client Zod validation, client form defaults, and the
Settings page form all carry the new systemEmailDisplayName field.
- The transport preview pre-block on /settings now includes a `from`
key showing exactly what the email service hands nodemailer — the
string when no display name is set, or { name, address } when it is.
- en.json carries the new label and placeholder. Other locales fall
back until translated (16 locales pending — separate follow-up).
## Conventions conformance (per docs/frontend-conventions.md)
- The pre-block I touched had three rule #1 violations (sx p,
borderRadius, backgroundColor); hoisted those to native props using
theme.shape.borderRadius. Other rule #1 violations elsewhere on this
page are pre-existing and intentionally left alone.
- No new sx-with-native-equivalents introduced.
- No color="text.X" shorthand introduced.
- No theme module import introduced.
gorkem-bwl
e71892d0bc