v0.256.0: the box sends its own sentence in the household's language (R-558 Part B)

MinAgent: 0.131.0 (unchanged). Needs hub v0.118.0+, which shipped first and
tolerates a box that sends none of this - every box in the fleet is that box
until this release reaches it.

The hub writes a household's e-mails in their language now, but about a third
of those mails carry a sentence the BOX composed, naming a drive, an app or a
number. The hub cannot translate one. So the box sends it twice.

- message_customer on POST /api/v1/event, omitempty. A HUNGARIAN household
  sends nothing extra at all, so its payload stays byte-for-byte what every box
  sends today and the hub's fallback path keeps being the one production
  exercises rather than a branch nobody takes.
- 19 producers render both sentences from ONE bundle key. `message` stays
  Hungarian always: it is what the operator is mailed and what the hub logs.
- customer.language bootstraps a new box - stored choice, then config, then
  Hungarian. The config value is NEVER written into settings.json: that would
  record a choice the household never made.

The Hungarian did not move, measured twice: the wire golden from the slice-2
base commit, and the Go parity gate over all 19 new keys.

Three guards had to learn the change and one caught me: the test seam now
carries the new field; the R-329 severity register reported two dynamic sites
as no longer existing the moment they moved off PushEvent (the walk now checks
36 severity literals, up from 20); and TestConfigLanguageIsWiredInMain reads
main.go, because cmd/ is gitignored and ripgrep does not.

A mistake, named: the first pass dropped displayName from three producers,
which would have mailed customers "Alkalmazás telepítve: %!s(MISSING)". Caught
reading the diff; now pinned by a test that refuses %!/MISSING/%s/%d in either
language.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0159rPz1ZhFKsS53msqPYxtS

controller/internal/notify/deadapp_test.go

@@ -11,7 +11,7 @@ import (
 func TestNotifyAppStartFailures_OneEventPerTransition(t *testing.T) {
 	n := New("http://hub", "key", "cust", nil, log.New(io.Discard, "", 0), false)
 	var events []string
-	n.pushFn = func(eventType, _, msg string, _ interface{}) {
+	n.pushFn = func(eventType, _, msg, _ string, _ interface{}) {
 		if eventType == "app_start_failed" {
 			events = append(events, msg)
 		}
@@ -45,7 +45,7 @@ func TestNotifyAppStartFailures_OneEventPerTransition(t *testing.T) {
 func TestNotifyAppStartFailures_FirstSeenDownFires(t *testing.T) {
 	n := New("http://hub", "key", "cust", nil, log.New(io.Discard, "", 0), false)
 	var count int
-	n.pushFn = func(eventType, _, _ string, _ interface{}) {
+	n.pushFn = func(eventType, _, _, _ string, _ interface{}) {
 		if eventType == "app_start_failed" {
 			count++
 		}
@@ -67,7 +67,7 @@ func TestNotifyAppStartFailures_FirstSeenDownFires(t *testing.T) {
 func TestNotifyAppStartFailures_StopStartCrashSequence(t *testing.T) {
 	n := New("http://hub", "key", "cust", nil, log.New(io.Discard, "", 0), false)
 	var count int
-	n.pushFn = func(eventType, _, _ string, _ interface{}) {
+	n.pushFn = func(eventType, _, _, _ string, _ interface{}) {
 		if eventType == "app_start_failed" {
 			count++
 		}
@@ -96,7 +96,7 @@ func TestNotifyAppStartFailures_StopStartCrashSequence(t *testing.T) {
 func TestNotifyAppStartFailures_HealthyNeverFires(t *testing.T) {
 	n := New("http://hub", "key", "cust", nil, log.New(io.Discard, "", 0), false)
 	var count int
-	n.pushFn = func(string, string, string, interface{}) { count++ }
+	n.pushFn = func(string, string, string, string, interface{}) { count++ }
 	n.NotifyAppStartFailures([]AppRunState{{Name: "radarr", Down: false}})
 	n.NotifyAppStartFailures([]AppRunState{{Name: "radarr", Down: false}})
 	if count != 0 {