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/cmd/controller/main.go

@@ -341,6 +341,11 @@ func main() {
 		logger.Fatalf("[FATAL] Failed to load settings from %s: %v", settingsPath, err)
 	}
 	sett.SetDebug(cfg.Logging.Level == "debug")
+	// v0.256.0 (R-558): the language the hub says this box should START in. Consulted by
+	// GetLanguage ONLY when the household has never chosen — an explicit choice in settings.json
+	// always wins, so a config pull cannot unseat it. A config change restarts the controller, so
+	// binding it once here is enough. Pinned by TestConfigLanguageIsWiredInMain.
+	sett.SetConfigLanguage(cfg.Customer.Language)
 
 	// --- Auto-discover storage paths from deployed apps ---
 	discoveredPaths := discoverHDDPaths(cfg.Paths.StacksDir, logger)