release: 0.6.0: Delivery detail page, DNS badge, machine metrics, wide layout

A page per delivery (`/deliveries/{id}`), reached from the *Details* link on
Added:
  - A page per delivery (`/deliveries/{id}`), reached from the *Details* link on
  - A **DNS** badge in the domain list, one per row, carrying the same
  - Machine metrics on the status page: a **Machine** card reporting the
  - An index of the current page's own sections in the navigation column, for the
Changed:
  - Every panel page is laid out in one column of the same width, so moving
  - The mark's small-size variant — the tab icon and the `SP` initials it
  - The stamp's `SELF-HOSTED SMTP RELAY` line is set at 11.5/0.15 instead of
  - The delivery log lists what identifies a message and nothing else: time,
  - Subjects are decoded for display as well as on the way in, so the rows the
  … (4 more in CHANGELOG)

Full detail: CHANGELOG.md (0.6.0).

internal/web/handlers_backup_test.go

@@ -117,6 +117,7 @@ func TestBackupPageOffersEncryption(t *testing.T) {
 	for _, want := range []string{
 		`name="encrypt"`, `name="password"`, `name="password_confirm"`,
 		`name="import_password"`, "data-encrypt-toggle", "data-encrypt-fields",
+		"data-import-password-fields",
 		fmt.Sprintf("at least %d characters", minSecretFilePasswordLen),
 		"The two passwords do not match.",
 	} {