CI: fail when the upstream name appears in a new string literal

tools/fork/name-check.py reads every string literal in crates/ (comments
and test directories skipped) and fails on any that carries the upstream
name without an entry in name-allowlist.txt. An upstream merge can bring
such strings in without a conflict, so it runs on every push and PR.

The first run found three the earlier sweeps missed, fixed here: the SMTP
HELP reply pointed at upstream's website (now brand_url!), the event
collector thread was named after upstream, and the FreeBSD default data
path still said /var/db/stalwart/ where Linux already had /var/lib/inbuxa/.

Two operator-visible defaults are allowlisted as open, pending a decision:
the log file prefix and the SQL stores' default database and user.

crates/jmap/src/registry/mapping/bootstrap.rs

@@ -657,7 +657,7 @@ fn map_dns_server(dns_server: &DnsServerBootstrap) -> Option<registry::schema::s
 // FreeBSD keeps variable application data under /var/db (hier(7))
 // rather than FHS /var/lib.
 const DEFAULT_DATA_PATH: &str = if cfg!(target_os = "freebsd") {
-    "/var/db/stalwart/"
+    "/var/db/inbuxa/"
 } else {
     "/var/lib/inbuxa/"
 };