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/logtail/logtail.go

@@ -1,9 +1,10 @@
 // Package logtail follows Postfix's mail.log and reconciles the send-log
-// delivery statuses the journal-milter could not know at receive time (spec
-// 7.3). A milter row starts life as "queued"; Postfix only decides sent /
-// deferred / bounced later, per recipient, and reports it in mail.log. This
-// package parses those lines by queue-id + recipient and advances the matching
-// rows, and prunes rows past the retention window.
+// delivery statuses the journal-milter could not know at receive time
+// (architecture.md § Persistence). A milter row starts life as "queued";
+// Postfix only decides sent / deferred / bounced later, per recipient, and
+// reports it in mail.log. This package parses those lines by queue-id +
+// recipient and advances the matching rows, and prunes rows past the retention
+// window.
 package logtail
 
 import (
@@ -17,14 +18,17 @@ import (
 	"strings"
 	"time"
 
-	"codeberg.org/mix/selfpost/internal/store"
+	"github.com/mixeme/selfpost/internal/store"
 )
 
-// StatusStore is the slice of the store the log-tailer needs. *store.Store
-// satisfies it.
+// StatusStore is the slice of the store the log-tailer needs: advancing
+// delivery statuses, pruning the retention window, and remembering how far into
+// mail.log it has read. *store.Store satisfies it.
 type StatusStore interface {
 	UpdateStatus(queueID, recipient, status string) (int64, error)
 	DeleteSendLogBefore(cutoff time.Time) (int64, error)
+	LogtailState(path string) (store.LogtailState, bool, error)
+	SaveLogtailState(path string, st store.LogtailState) error
 }
 
 // pollInterval is how often the tail loop checks for new bytes / rotation. It
@@ -36,7 +40,7 @@ const (
 	// startup). The window itself is configurable; the cadence need not be.
 	retentionInterval = 6 * time.Hour
 	// defaultRetentionDays applies when the configured value is unset/invalid
-	// (spec 7.3).
+	// (README § Environment variables: SEND_LOG_RETENTION_DAYS).
 	defaultRetentionDays = 90
 )
 
@@ -47,7 +51,13 @@ const (
 //
 // The "<queue-id>: to=<addr>, …, status=<word>" shape is specific to the
 // delivery agents; qmgr/smtpd/cleanup lines do not match.
-var deliveryRe = regexp.MustCompile(`\b([0-9A-Za-z]+): to=<([^>]*)>,.*\bstatus=(\w+)`)
+//
+// The run before status= is lazy on purpose. Postfix appends the remote
+// server's reply verbatim, so a greedy match would take the *last* status= on
+// the line — and that one can come from the reply text, which the far end
+// controls. A bounce whose reply quoted "status=sent" would then be filed as a
+// success. The real field is always the first one after to=<…>.
+var deliveryRe = regexp.MustCompile(`\b([0-9A-Za-z]+): to=<([^>]*)>,.*?\bstatus=(\w+)`)
 
 // parseDelivery extracts (queue-id, recipient, status) from a mail.log line.
 // ok is false for lines that are not recognised delivery results.
@@ -73,12 +83,13 @@ func parseDelivery(line string) (queueID, recipient, status string, ok bool) {
 }
 
 // Run follows path and updates send-log statuses until ctx is cancelled, while
-// a background sweep prunes rows older than retentionDays. It returns nil on a
-// clean shutdown.
+// a background sweep prunes rows older than retentionDays. Reading resumes at
+// the offset the previous run persisted, so a restart parses the delivery lines
+// written while the panel was down. It returns nil on a clean shutdown.
 func Run(ctx context.Context, path string, st StatusStore, retentionDays int) error {
 	go retentionLoop(ctx, st, retentionDays)
 
-	return follow(ctx, path, func(line string) {
+	return follow(ctx, path, &tracker{st: st, path: path}, func(line string) {
 		queueID, recipient, status, ok := parseDelivery(line)
 		if !ok {
 			return
@@ -120,10 +131,10 @@ func retentionLoop(ctx context.Context, st StatusStore, retentionDays int) {
 }
 
 // TailLines returns up to n of the most recent lines from path, for the
-// panel's mail.log monitoring view (spec 7.2.13). It is a one-shot,
-// point-in-time read on request — unrelated to the background follow loop
-// above — that reads backwards in chunks so it stays cheap against a
-// multi-megabyte log rather than reading the whole file every poll.
+// panel's mail.log monitoring view (architecture.md § Panel HTTP surface). It
+// is a one-shot, point-in-time read on request — unrelated to the background
+// follow loop above — that reads backwards in chunks so it stays cheap against
+// a multi-megabyte log rather than reading the whole file every poll.
 func TailLines(path string, n int) ([]string, error) {
 	f, err := os.Open(path)
 	if err != nil {
@@ -166,10 +177,11 @@ func TailLines(path string, n int) ([]string, error) {
 }
 
 // follow tails path line by line, calling handle for each complete line, until
-// ctx is cancelled. It starts at end-of-file (so a restart does not reprocess
-// history) and reopens the file when it is rotated (inode change from
+// ctx is cancelled. Where it starts is tr's decision (a persisted offset, the
+// start of a file that changed while the panel was down, or end-of-file on a
+// first ever run); it reopens the file when it is rotated (inode change from
 // logrotate's create, or truncation from copytruncate) so nothing is missed.
-func follow(ctx context.Context, path string, handle func(string)) error {
+func follow(ctx context.Context, path string, tr *tracker, handle func(string)) error {
 	var (
 		f       *os.File
 		r       *bufio.Reader
@@ -199,7 +211,7 @@ func follow(ctx context.Context, path string, handle func(string)) error {
 
 	// The container may start before Postfix has created mail.log; wait for it.
 	for {
-		if err := openAt(0, io.SeekEnd); err == nil {
+		if err := openAt(0, io.SeekStart); err == nil {
 			break
 		}
 		select {
@@ -208,6 +220,10 @@ func follow(ctx context.Context, path string, handle func(string)) error {
 		case <-time.After(pollInterval):
 		}
 	}
+	if _, err := f.Seek(tr.resume(f), io.SeekStart); err != nil {
+		log.Printf("log-tailer: seek %s: %v", path, err)
+	}
+	r.Reset(f) // the reader buffered from the pre-seek position
 	defer func() {
 		if f != nil {
 			f.Close()
@@ -231,11 +247,20 @@ func follow(ctx context.Context, path string, handle func(string)) error {
 		}
 	}
 
+	// read returns how many bytes of the open file have actually been consumed:
+	// the descriptor position less the partial line bufio handed back at EOF,
+	// which is re-read (and completed) on the next drain or the next start.
+	read := func() int64 {
+		pos, _ := f.Seek(0, io.SeekCurrent)
+		return pos - int64(len(pending))
+	}
+
 	ticker := time.NewTicker(pollInterval)
 	defer ticker.Stop()
 	for {
 		select {
 		case <-ctx.Done():
+			tr.record(f, read(), true) // shutdown: the next start resumes here
 			return nil
 		case <-ticker.C:
 			drain()
@@ -252,8 +277,12 @@ func follow(ctx context.Context, path string, handle func(string)) error {
 				drain()
 				if err := openAt(0, io.SeekStart); err != nil {
 					log.Printf("log-tailer: reopen %s: %v", path, err)
+					continue
 				}
+				tr.adopt(f)
+				continue
 			}
+			tr.record(f, read(), false)
 		}
 	}
 }