base-trixie: the image on Debian trixie, Postfix 3.10.13; Received: hidden on 465/587

The runtime base is debian:trixie-slim, the build stage golang:1.26-trixie:
Postfix 3.10.13 with upstream's 2026 security fixes up to the August
batch, libmilter 8.18.1, OpenSSL 3.5. Every citation of another program in
code, scripts and documents was re-read against the trixie sources
(dev/upstream; bookworm's kept in dev/upstream-bookworm) and updated;
development.md's cited-package table holds the trixie versions.

What the re-reading changed in behaviour:
- logtail: reject lines with sasl_method/sasl_username/sasl_sender
  (smtpd_check.c:1019-1026); cleanup's "removed (canceled)" forgets a
  port-25 id (cleanup_api.c:363-364).
- internal/postfix/retry.go reads postconf's stdout only: since 3.9 a
  deprecated-parameter warning on stderr made one value too many and the
  panel fell back to the compiled-in retry policy.
- logrotate-loop.sh: logrotate 3.22 exits 1 when it ignores a config;
  the loop refuses on that output whatever the status.
- postfix-config.sh: cyrus_sasl_config_path set explicitly (bookworm's
  07_sasl_config.diff is gone); maillog_file_permissions=0640; mynetworks
  explicit; Dockerfile: SYNC_CHROOT= in /etc/default/postfix,
  opendkim-tools dropped, openssl named, systemd-standalone-sysusers so
  cron does not bring the whole of systemd.
- The selfpost group is 10998, outside the system range 100-999: in
  trixie a package took 998 and the build failed (owner's decision:
  a conflict-free id, the distribution's own ids untouched). The
  entrypoint hands /data back by name when the user or the group differs.
  Guide, backup refusal text, help (design commit 68ec8b2), e2e.
- smtpd_hide_client_session=yes on smtps and submission (owner's
  decision): Received: names no client, TLS, login or protocol; port 25
  keeps the full header. e2e checks both.
- test/upstream/opendkim-probe.sh makes keys with openssl genrsa.

Tests: on the server, make e2e exit 0 (674 s, the image built on trixie),
go vet + go test 27 packages ok. CHANGELOG [Unreleased], guide,
architecture.md, security.md, roadmap.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/postfix/inbound.go

@@ -55,7 +55,7 @@ func (p *Postfix) RebuildInboundMaps(routes []InboundRoute) error {
 	return p.reload()
 }
 
-// Postfix 3.7.11, man/man5/postconf.5: a relay_domains table "is matched when
+// Postfix 3.10.13, man/man5/postconf.5: a relay_domains table "is matched when
 // a (parent) domain appears as lookup key", the value unused; relay_recipient_maps
 // is used as a list, "@domain" its wild-card (src/global/mail_addr_find.c,
 // MA_FIND_AT_DOMAIN, the exact domain only). man/man5/transport.5: "domain
@@ -104,7 +104,7 @@ func renderInboundMaps(routes []InboundRoute) (relay, transport, recipients, tls
 // what disable the MX lookup, so the operator's explicit upstream is used as
 // given; they also delimit a bare IPv6 address.
 //
-// Postfix 3.7.11, src/smtp/smtp_connect.c: no MX lookup for a destination that
+// Postfix 3.10.13, src/smtp/smtp_connect.c: no MX lookup for a destination that
 // starts with "["; src/util/host_port.c, host_port(): "[host]:port", the host
 // a name or an address ("ipv6:" in front is optional), checked by
 // valid_hostaddr().