release: 0.5.0: Pre-1.0 security review, domain-admin role, doc consolidation

A bounce could be recorded as a successful delivery. The log-tailer's
Fixed:
  - A bounce could be recorded as a successful delivery. The log-tailer's
  - Log-tailer resumes where it stopped instead of jumping to end-of-file on
  - Level-2 rate limit no longer overshoots under concurrency: messages that
Changed:
  - The project has a single public home: `github.com/mixeme/selfpost`. Codeberg
  - Code comments no longer cite the archived specification. References like
  - `docs/code-review.md` is gone. Its plan is finished — phases 0 (bar the
  - `docs/architecture.md` gained a *Code layers* section: a diagram of
  - Phase 1 doc/code hygiene (`docs/code-review.md`): removed ~30 stale
  … (1 more in CHANGELOG)
Security:
  - Pre-release security review (plan § D, model Fable, 2026-08-06): full pass
  - `saslpasswd2` argv: the application login is now passed after a `--`
Added:
  - Optional password encryption for the two secret-bearing downloads (plan
  - Domain import accepts an encrypted export: the envelope is detected by its
  - `selfpost-backup` writes encrypted archives and reads them back:
  - `TestParseDelivery` covers the exotic mail.log shapes the review asked for
  - docs: README *Encrypting a backup or export*; `docs/security.md` §
  … (14 more in CHANGELOG)
Removed:
  - docs: `security.md` — accepted risk «restore old backup revives session rows»
Changed:
  - docs: `implementation-plan.md` trimmed to the sole open v1.x gate — pre-release
  - docs: `architecture.md` — sessions (SQLite, idle renew, password change),
  - docs: `development.md` — expanded e2e stack and `release.yml` matrix workflow.
  - docs: `security.md` — accepted risk for send-log rows stuck at `queued` after
  - docs: `roadmap.md` — optional send-log / `mail.log` follow-ups under v1.x tail.
  … (10 more in CHANGELOG)

Full detail: CHANGELOG.md (0.5.0).

internal/store/sendlog_test.go

@@ -5,8 +5,8 @@ import (
 	"time"
 )
 
-// readSendLog returns every send_log row ordered by id. Phase 6 has no read
-// query yet (the monitoring UI is Phase 7), so tests read the table directly.
+// readSendLog returns every send_log row ordered by id. The monitoring UI has
+// no equivalent read query, so tests read the table directly.
 type sendLogRow struct {
 	QueueID  string
 	Domain   string
@@ -40,7 +40,8 @@ func readSendLog(t *testing.T, s *Store) []sendLogRow {
 func TestInsertQueuedAndUpdateStatus(t *testing.T) {
 	st := openTestStore(t)
 
-	// Two recipients on the same queue-id → two independent rows (spec 7.3.3).
+	// Two recipients on the same queue-id → two independent rows (architecture.md
+	// § Persistence).
 	for _, to := range []string{"a@example.net", "b@example.net"} {
 		if err := st.InsertQueued(SendLogEntry{
 			QueueID:  "ABC123",