betterbird: keep the reminder test's update check off so no About window takes the screen (hq issue 345)

A fresh profile has never checked for updates, so Betterbird checked at the
test's start, found a newer build published and opened its About window on the
operator's screen instead of leaving the reminder to show. The test's own
preferences now also come last in its user.js, so nothing declared or carried
overrides them.

modules/betterbird/README.md

@@ -78,7 +78,11 @@ under `/run/user/<uid>/mesh-betterbird-reminder-test/`, as the user unit
 `mesh-betterbird-reminder-test` (ended after 10 minutes at most). The profile holds the module's
 user.js and one calendar: a local `.ics` file with one event, "Mesh reminder test", whose reminder is
 due `after` seconds from the call (default 40). `carry` copies named preferences of the operator's
-profile into it (a theme, a colour switch), under the same limits as `betterbird_prefs`. Then:
+profile into it (a theme, a colour switch), under the same limits as `betterbird_prefs`. The test's own
+preferences come last in its user.js, so nothing declared or carried overrides them; one of them turns
+Betterbird's update check off (`betterbird.update.checkIntervalDays` 0), because a fresh profile checks
+at its start and, when a newer build is published, opens the About window on the operator's screen
+(seen 2026-10-12). Then:
 
 - `xorg_windows` with class `Calendar` answers the reminder window: role `AlarmWindow`, type `Dialog`,
   its depth (32: a visual with alpha, which the compositor blends), its map state;

modules/betterbird/cmd/betterbird-tools/betterbird_test.go

@@ -238,6 +238,13 @@ func TestTheReminderTestTouchesNothingOfTheOperatorsProfile(t *testing.T) {
 		!strings.Contains(string(user), "file:///run/user/1000/"+testUnit+"/test.ics") || strings.Contains(string(user), "someone@") {
 		t.Fatalf("%s", user)
 	}
+	// Betterbird's update check stays off, so no About window opens on the operator's screen, and the
+	// test's own preferences come last, so nothing carried or declared overrides them.
+	if !strings.Contains(string(user), `"betterbird.update.checkIntervalDays", 0`) ||
+		strings.Index(string(user), "extensions.activeThemeID") > strings.Index(string(user), "calendar.registry.meshtest.uri") ||
+		strings.Index(string(user), `"calendar.alarms.show"`) > strings.Index(string(user), "calendar.registry.meshtest.uri") {
+		t.Fatalf("%s", user)
+	}
 	// The event starts 10 minutes after the reminder, which is due 40 s from now.
 	if !strings.Contains(string(cal), "DTSTART:20270115T081040Z") || !strings.Contains(string(cal), "TRIGGER:-PT10M") ||
 		a.Due != "2027-01-15T08:00:40Z" {

modules/betterbird/cmd/betterbird-tools/reminder.go

@@ -55,6 +55,11 @@ func ics(now time.Time, after time.Duration, stamp string) string {
 }
 
 // testPrefs are the test profile's own preferences: its one calendar, and no first-run questions.
+//
+// betterbird.update.checkIntervalDays 0 is Betterbird's own switch for its update check (MailGlue): a
+// fresh profile has never checked, so Betterbird checks at its start and, when betterbird.eu publishes a
+// newer build than the installed one, opens the About window on the operator's screen and gives it the
+// focus (seen on the workstation 2026-10-12, novox/hq issue 345). The test is about the reminder only.
 func testPrefs(calendar string) string {
 	return strings.Join([]string{
 		`user_pref("calendar.registry.meshtest.type", "ics");`,
@@ -68,6 +73,7 @@ func testPrefs(calendar string) string {
 		`user_pref("datareporting.policy.dataSubmissionEnabled", false);`,
 		`user_pref("toolkit.telemetry.reportingpolicy.firstRun", false);`,
 		`user_pref("app.update.auto", false);`,
+		`user_pref("betterbird.update.checkIntervalDays", 0);`,
 		`user_pref("mail.rights.version", 1);`,
 		"",
 	}, "\n")
@@ -125,11 +131,13 @@ func (m *Machine) ReminderTest(after time.Duration, carry []string, stop bool) (
 	if err := os.WriteFile(calendar, []byte(ics(now, after, strconv.FormatInt(now.Unix(), 10))), 0o600); err != nil {
 		return a, err
 	}
-	user := testPrefs(strings.TrimPrefix(calendar, m.Root))
+	// The module's user.js first, then what is carried, then the test's own preferences: the last
+	// statement wins, so neither can take the test's calendar or its quiet start away.
+	user := ""
 	if mine, err := readBounded(m.home(declared)); err == nil && validUserJS(string(mine)) == nil {
-		user = string(mine) + "\n" + user
+		user = string(mine) + "\n"
 	}
-	user += strings.Join(carried, "\n") + "\n"
+	user += strings.Join(carried, "\n") + "\n" + testPrefs(strings.TrimPrefix(calendar, m.Root))
 	if err := os.WriteFile(filepath.Join(dir, "profile", "user.js"), []byte(user), 0o600); err != nil {
 		return a, err
 	}