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

.claude/rules/hub.md

@@ -50,7 +50,9 @@ cannot be read off the code:
   the blocked thread remains. Liveness is decided from `/proc` and kernel state, never by reading or
   writing the filesystem.
 - New event types must enter `allowedEventTypes` **and** `customerMessages` together, or `POST
-  /event` 400s.
+  /event` 400s. **From v0.118.0 the `customerMessages` half is a line in `internal/i18n/locales/hu.json`
+  (`mail.event.<type>`) AND its English twin** — the map is derived from the bundle, and the
+  missing-key gate is held at zero. Customer copy lives in the bundle; the operator's mails do not.
 - Status logic: OK (report younger than `alerting.stale_threshold`), WARN (past the threshold or
   `health=warn`), DOWN (past 2× the threshold or `health=fail`). The threshold is **configuration**
   (`manifests/hub.yaml`; 45 m by operator ruling 2026-09-17, R-549), and the display