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/logtail.go

@@ -0,0 +1,54 @@
+package store
+
+import (
+	"database/sql"
+	"errors"
+	"fmt"
+	"time"
+)
+
+// LogtailState is the persisted read position of the mail.log tailer: how far
+// into the log it had got, and a fingerprint of the file that offset refers to.
+// It lets the tailer resume after a panel restart instead of jumping to
+// end-of-file and losing the delivery lines written while it was down.
+type LogtailState struct {
+	Fingerprint string
+	Offset      int64
+}
+
+// LogtailState returns the stored read position for path. ok is false the first
+// time a path is followed (nothing persisted yet), which the tailer treats as
+// "start at the end".
+func (s *Store) LogtailState(path string) (LogtailState, bool, error) {
+	var st LogtailState
+	err := s.db.QueryRow(
+		`SELECT fingerprint, read_offset FROM logtail_state WHERE path = ?`,
+		path,
+	).Scan(&st.Fingerprint, &st.Offset)
+	if errors.Is(err, sql.ErrNoRows) {
+		return LogtailState{}, false, nil
+	}
+	if err != nil {
+		return LogtailState{}, false, fmt.Errorf("read logtail state for %q: %w", path, err)
+	}
+	return st, true, nil
+}
+
+// SaveLogtailState records the tailer's read position for path, replacing any
+// previous one. It is called on a timer while tailing, so it is a single small
+// upsert rather than a transaction.
+func (s *Store) SaveLogtailState(path string, st LogtailState) error {
+	_, err := s.db.Exec(
+		`INSERT INTO logtail_state (path, fingerprint, read_offset, updated_at)
+		 VALUES (?, ?, ?, ?)
+		 ON CONFLICT(path) DO UPDATE SET
+		     fingerprint = excluded.fingerprint,
+		     read_offset = excluded.read_offset,
+		     updated_at  = excluded.updated_at`,
+		path, st.Fingerprint, st.Offset, time.Now().UTC().Format(time.RFC3339),
+	)
+	if err != nil {
+		return fmt.Errorf("save logtail state for %q: %w", path, err)
+	}
+	return nil
+}