release: 1.9.2: Review pass: port-25 milters, DMARC validation, rate-limit fix

Review pass over `1.4.0`…`1.9.1`: port 25 no longer shares the submission milter chain, DMARC reports are validated before they are stored, and the auto rate limit is correct for a non-default level-1 window. Schema migration `0010` (index only). Upgrading is a tag bump.
Added:
  - SQLite migration `0010_send_log_app_login_index.sql` —
  - DMARC aggregate reports are accepted as **zip** as well as gzip or plain XML
  - e2e: `checkPort25ConfigCombinations` regenerates the Postfix configuration
Changed:
  - README hero line and a **Positioning** block in `docs/product.md` record the
Fixed:
  - The setup account's password is hashed at bcrypt cost `12` like every other
  - Login/setup rate limiter: protecting blocked buckets from eviction is now
  - `postqueue -p` output is bounded to 4 MiB (the timeout alone left the size of
  - [schema-migrations.md](docs/schema-migrations.md): the schema section was
  - postqueue reader is now time-bounded: `postqueue -p` runs under a 5-second
  … (11 more in CHANGELOG)
Changed:
  - [roadmap.md](docs/roadmap.md) now carries everything the 2026-08-19 code
  - Extracted `internal/configsafe` — the empty-value and forbidden-character
  - Build, deploy and migration comments no longer cite the archived
  - Dropped the `parseDomainRateLimitForm` / `parseAppRateLimitForm` pass-through
  - Extracted shared helpers: `internal/atomicfile` (atomic temp-write+rename) and
  … (7 more in CHANGELOG)
Removed:
  - Unused legacy asset `docs/assets/icon.png` (superseded by the four brand SVGs
  - Plan documents for already-shipped features: `domain-stats-auto-ratelimit`,

Full detail: CHANGELOG.md (1.9.2).

internal/postfix/postfix.go

@@ -7,10 +7,12 @@ package postfix
 
 import (
 	"fmt"
-	"os/exec"
 	"path/filepath"
 	"sort"
 	"strings"
+
+	"github.com/mixeme/selfpost/internal/configsafe"
+	"github.com/mixeme/selfpost/internal/supervisor"
 )
 
 // Postfix manages the on-disk Postfix state the panel is responsible for. After
@@ -122,6 +124,15 @@ func appendUnique(list []string, v string) []string {
 	return append(list, v)
 }
 
+// What may never reach a sender-map line: whitespace and the newline that would
+// end it, the comma that separates values, the colon a lookup key cannot carry,
+// and the backslash. A login additionally may not carry "@" — that would make it
+// look like an address.
+const (
+	senderMapAddressForbidden = " \t\r\n,:\\"
+	senderMapLoginForbidden   = " \t\r\n,:@\\"
+)
+
 // assertMapSafe rejects any address/login value that could break out of a single
 // map line or inject a directive. Addresses are validated to a strict whitelist
 // (letters, digits, '@', '.', '-', '_', '+') and logins to an even stricter one
@@ -129,14 +140,11 @@ func appendUnique(list []string, v string) []string {
 // letting whitespace, a newline or a comma (the value separator) through into
 // the file (security.md).
 func assertMapSafe(address, login string) error {
-	if address == "" || login == "" {
-		return fmt.Errorf("postfix: empty address or login")
+	if err := configsafe.Token("address", address, senderMapAddressForbidden); err != nil {
+		return fmt.Errorf("postfix: %w", err)
 	}
-	if strings.ContainsAny(address, " \t\r\n,:\\") {
-		return fmt.Errorf("postfix: unsafe character in address %q", address)
-	}
-	if strings.ContainsAny(login, " \t\r\n,:@\\") {
-		return fmt.Errorf("postfix: unsafe character in login %q", login)
+	if err := configsafe.Token("login", login, senderMapLoginForbidden); err != nil {
+		return fmt.Errorf("postfix: %w", err)
 	}
 	return nil
 }
@@ -154,17 +162,5 @@ func assertMapSafe(address, login string) error {
 // Arguments are fixed literals — no user input is interpolated into the command,
 // and it never goes through a shell (security.md).
 func reloadViaSupervisor() error {
-	cmd := exec.Command("supervisorctl",
-		"-c", "/etc/supervisor/supervisord.conf",
-		"start", "postfix-reload")
-	out, err := cmd.CombinedOutput()
-	if err != nil {
-		// A reload already in flight is not a failure: that pending run reloads
-		// Postfix after our file is in place (the file is written before this).
-		if strings.Contains(string(out), "already started") {
-			return nil
-		}
-		return fmt.Errorf("reload postfix via supervisor: %w: %s", err, strings.TrimSpace(string(out)))
-	}
-	return nil
+	return supervisor.Start("postfix-reload")
 }