hub v0.118.0: the household's e-mails follow the household's language (R-558 Part A)

The hub has written every customer e-mail in Hungarian whatever the box was set
to. The box has published its language since controller v0.247.0; nothing read
it. Now it does.

Nothing an operator reads changes. The Hungarian mails are byte-identical, and
that is a diff rather than a reading: 56 goldens per language captured from
v0.117.0 BEFORE any string moved, and all 56 Hungarian ones pass unchanged after
every sentence was routed through the new bundle.

- internal/i18n: flat bundle, 79 keys, hu authoritative + hu fallback, ceiling 0.
- customerMessages/severityLabels are DERIVED from the bundle, so a sentence is
  written in one place and all 40+ tests that read those maps still work.
- Language order: last reported -> created-with -> hu. reports.language defaults
  to EMPTY, never hu: "never told us" is not "chose Hungarian".
- message_customer on POST /api/v1/event, additive and optional forever, for the
  sentences the box composes and the hub cannot translate.
- The bind page is per-language, and its `expired` state stays Hungarian: it is
  the state an unknown token lands in, so rendering a real English customer's
  token in English would make the LANGUAGE answer what the TEXT refuses to.

Two defects found inside the release:
- R-581: the newest report was picked by received_at, which has SECOND
  granularity, so same-second reports tied and the winner was arbitrary. Ordered
  by the autoincrement id now. GetCustomers() still has the shape - row open.
- R-582: the English copy-guard stems, ported word for word from Hungarian,
  convicted 141 honest sentences. The English claim is a phrase with a modal.

R-555 closed: the language allowlist entry is out of wire_contract_gate.py.
hub_copy_gate.py follows the sentences into the bundle - without that it would
have scanned four files that no longer hold any customer text and reported
success. Three new decoys incl. an innocent control.

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

hub/internal/notify/node_liveness_cooldown_test.go

@@ -19,7 +19,12 @@ func TestOperatorCooldown_NodeLivenessBypassesQuietHour(t *testing.T) {
 	d := NewDispatcher(st, "test-key", "from@felhom.eu", "op@felhom.eu", true, log.New(io.Discard, "", 0))
 	var mu sync.Mutex
 	sent := 0
-	d.sendEmailFn = func(string, string, string, map[string]string) error { mu.Lock(); defer mu.Unlock(); sent++; return nil }
+	d.sendEmailFn = func(string, string, string, map[string]string) error {
+		mu.Lock()
+		defer mu.Unlock()
+		sent++
+		return nil
+	}
 	count := func() int { mu.Lock(); defer mu.Unlock(); return sent }
 
 	// The previous node_stale mail went 39 minutes ago.