release: 2.2.0: a message's page keeps its delivery log

delivery-log-storage (docs/plans/delivery-log-storage.md, 8/8), at the
owner's word (2026-10-12, "Да").

  - The log tailer stores what Postfix writes about queued outbound
    messages; a message's page reads it from the database, so the
    Delivery log box no longer empties when mail.log rotates. The lines
    live as long as the send-log row and go with it.
  - Mail that came in on port 25 is not stored.
  - Migration 0003 (send_log_lines), DDL only.

What an operator should know: the stored lines are 1-2 KB a message
and are in a full backup, which mail.log is not (security.md). A
message accepted before this version shows its lines only while they
are in the current file.

Cut: CHANGELOG [Unreleased] -> [2.2.0]; image pin 2.2.0 in compose,
README, guide; version table, roadmap, plan status. No tag: the owner
tags when he decides to (2026-10-11), so there is no image of this
version until then.

On the test server, on a990e7c: go vet ./... ok, go test ./... ok
(22 packages), make e2e ok.

Full detail: CHANGELOG.md (2.2.0).

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

deploy/docker-compose.yml

@@ -21,7 +21,7 @@
 
 services:
   selfpost:
-    image: ghcr.io/mixeme/selfpost:2.1.0
+    image: ghcr.io/mixeme/selfpost:2.2.0
     restart: unless-stopped
     environment:
       SELFPOST_HOSTNAME: "${SELFPOST_HOSTNAME:?set the mail/panel hostname, e.g. mail.example.com}"