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/web/selfbind.go

@@ -4,12 +4,15 @@ import (
 	"crypto/subtle"
 	"html/template"
 	"net/http"
+	"regexp"
 	"strings"
 	"sync"
 	"time"
 
 	"gitea.dooplex.hu/admin/felhom-hub/internal/configgen"
 	"gitea.dooplex.hu/admin/felhom-hub/internal/store"
+
+	"gitea.dooplex.hu/admin/felhom-hub/internal/i18n"
 )
 
 // selfbind.go — the CUSTOMER side of self-bind (v0.66.0, R-27 slice 1): the PUBLIC /bind/<token> page.
@@ -97,14 +100,50 @@ type bindPageData struct {
 	State  string // "form" | "success" | "expired" | "consumed" | "locked"
 	Token  string // echoed into the form action (the capability itself; already in the URL)
 	Failed bool   // generic factor-check failure (form state only)
+	// Lang is the language to render in. It is the CUSTOMER'S CREATION-TIME language and nothing
+	// else: no box has reported yet at bind time, and this page deliberately offers no switch —
+	// the person opening it is a stranger holding a capability URL, exactly like the guest share
+	// pages, and a language control here would be a setting a stranger could touch.
+	Lang string
 }
 
-var bindTemplate = template.Must(template.New("bind").Parse(bindPageHTML))
+// bindTemplates holds ONE PARSED TEMPLATE PER LANGUAGE, with the bundle's text substituted into the
+// markup BEFORE html/template parses it.
+//
+// This is the controller's design (10-localisation.md rule 3) and it is chosen for the same reason:
+// the Hungarian set is parsed from exactly the bytes the page carried before it was converted, in
+// the same escaping contexts, so the Hungarian page is byte-identical by construction rather than by
+// inspection. A runtime T function would route every string through the contextual escaper and move
+// bytes (`—`, quotes) in ways nobody would notice until a customer saw them.
+var bindTemplates = buildBindTemplates()
+
+func buildBindTemplates() map[string]*template.Template {
+	out := make(map[string]*template.Template, len(i18n.Supported))
+	b := i18n.Shared()
+	for _, lang := range i18n.Supported {
+		html := i18nMarkerRe.ReplaceAllStringFunc(bindPageHTML, func(m string) string {
+			return b.Msg(lang, i18nMarkerRe.FindStringSubmatch(m)[1])
+		})
+		// Must: a template that fails to parse is a broken build, not a broken request. It fails
+		// at startup and in every test, rather than serving a stranger a blank page.
+		out[lang] = template.Must(template.New("bind-" + lang).Parse(html))
+	}
+	return out
+}
+
+// i18nMarkerRe matches a {{T "key"}} marker. Strict on purpose: a malformed marker is NOT
+// substituted, so it reaches html/template as a call to an undefined function and the build fails
+// loudly — never a marker shown to a customer.
+var i18nMarkerRe = regexp.MustCompile(`\{\{\s*T\s+"([A-Za-z0-9_.\-]+)"\s*\}\}`)
 
 func (s *Server) renderBind(w http.ResponseWriter, status int, data bindPageData) {
+	tmpl, ok := bindTemplates[i18n.Normalize(data.Lang)]
+	if !ok {
+		tmpl = bindTemplates[i18n.Default]
+	}
 	w.Header().Set("Content-Type", "text/html; charset=utf-8")
 	w.WriteHeader(status)
-	if err := bindTemplate.Execute(w, data); err != nil {
+	if err := tmpl.Execute(w, data); err != nil {
 		s.logger.Printf("[ERROR] rendering /bind page: %v", err)
 	}
 }
@@ -114,14 +153,14 @@ func (s *Server) renderBind(w http.ResponseWriter, status int, data bindPageData
 // customer self-bind). Reached only via isPublicBindPath — auth + CSRF exempt at the gate sites.
 func (s *Server) handleBind(w http.ResponseWriter, r *http.Request) {
 	if s.bindLimiter != nil && !s.bindLimiter.allow(bindClientIP(r)) {
-		s.renderBind(w, http.StatusTooManyRequests, bindPageData{State: "expired"})
+		s.renderBind(w, http.StatusTooManyRequests, bindPageData{State: "expired", Lang: i18n.Default})
 		return
 	}
 	token := strings.TrimPrefix(r.URL.Path, "/bind/")
 	// A trailing segment only — reject anything with further path structure (defence in depth atop
 	// the ServeMux path-clean; the token is a flat hex string).
 	if token == "" || strings.Contains(token, "/") {
-		s.renderBind(w, http.StatusNotFound, bindPageData{State: "expired"})
+		s.renderBind(w, http.StatusNotFound, bindPageData{State: "expired", Lang: i18n.Default})
 		return
 	}
 	hash := selfBindHash(token)
@@ -133,22 +172,40 @@ func (s *Server) handleBind(w http.ResponseWriter, r *http.Request) {
 	}
 	now := time.Now()
 
+	// THE LANGUAGE IS ITSELF AN ORACLE, so it is resolved with the same care as the text (R-558).
+	//
+	// This page folds an UNKNOWN token into "expired" precisely so a stranger cannot learn whether a
+	// link was ever real. If the page then rendered a real customer's token in English and an unknown
+	// one in Hungarian, the LANGUAGE would answer the question the TEXT refuses to — for every
+	// customer who is not Hungarian. So:
+	//
+	//   - the "expired" state ALWAYS renders in the default language, because that is the state an
+	//     unknown token lands in and the two must be indistinguishable;
+	//   - every other state already discloses that the token is real (its text says so), so those
+	//     may follow the customer.
+	//
+	// Pinned by TestBindExpiredIsAlwaysDefaultLanguage.
+	lang := i18n.Default
+	if tok != nil {
+		lang = s.store.CustomerLanguage(tok.CustomerID)
+	}
+
 	// Terminal link states — identical for GET and POST, no factor check attempted. An unknown token
 	// (nil) is folded into "expired": no oracle for "was this link ever real".
 	switch {
 	case tok == nil || tok.Expired(now):
-		s.renderBind(w, http.StatusOK, bindPageData{State: "expired"})
+		s.renderBind(w, http.StatusOK, bindPageData{State: "expired", Lang: i18n.Default})
 		return
 	case tok.Consumed():
-		s.renderBind(w, http.StatusOK, bindPageData{State: "consumed"})
+		s.renderBind(w, http.StatusOK, bindPageData{State: "consumed", Lang: lang})
 		return
 	case tok.Locked:
-		s.renderBind(w, http.StatusOK, bindPageData{State: "locked"})
+		s.renderBind(w, http.StatusOK, bindPageData{State: "locked", Lang: lang})
 		return
 	}
 
 	if r.Method != http.MethodPost {
-		s.renderBind(w, http.StatusOK, bindPageData{State: "form", Token: token})
+		s.renderBind(w, http.StatusOK, bindPageData{State: "form", Token: token, Lang: lang})
 		return
 	}
 
@@ -181,10 +238,10 @@ func (s *Server) handleBind(w http.ResponseWriter, r *http.Request) {
 		// COUNTS only — never which factor failed, never the secrets, never the raw token.
 		s.logger.Printf("[WARN] self-bind attempt %d/%d failed for token %s… (customer %s)", attempts, store.SelfBindMaxAttempts, hash[:8], tok.CustomerID)
 		if locked {
-			s.renderBind(w, http.StatusOK, bindPageData{State: "locked"})
+			s.renderBind(w, http.StatusOK, bindPageData{State: "locked", Lang: lang})
 			return
 		}
-		s.renderBind(w, http.StatusOK, bindPageData{State: "form", Token: token, Failed: true})
+		s.renderBind(w, http.StatusOK, bindPageData{State: "form", Token: token, Failed: true, Lang: lang})
 		return
 	}
 
@@ -197,14 +254,14 @@ func (s *Server) handleBind(w http.ResponseWriter, r *http.Request) {
 	}
 	if !consumed {
 		// Lost the race (a concurrent request consumed it) — it is already being bound.
-		s.renderBind(w, http.StatusOK, bindPageData{State: "consumed"})
+		s.renderBind(w, http.StatusOK, bindPageData{State: "consumed", Lang: lang})
 		return
 	}
 	if err := s.store.BindAppliance(appliance.ID, tok.CustomerID, "appliance", ""); err != nil {
 		// Rare: the appliance became unbindable (operator discarded it) between lookup and bind. The
 		// token is spent; surface a neutral generic failure rather than an appliance-state oracle.
 		s.logger.Printf("[WARN] self-bind: BindAppliance %d → %s failed after factor match: %v", appliance.ID, tok.CustomerID, err)
-		s.renderBind(w, http.StatusOK, bindPageData{State: "form", Failed: true})
+		s.renderBind(w, http.StatusOK, bindPageData{State: "form", Failed: true, Lang: lang})
 		return
 	}
 	if _, err := s.store.SaveEvent(tok.CustomerID, "appliance_bound", "info",
@@ -212,7 +269,7 @@ func (s *Server) handleBind(w http.ResponseWriter, r *http.Request) {
 		s.logger.Printf("[WARN] self-bind: save event for %s: %v", tok.CustomerID, err)
 	}
 	s.logger.Printf("[INFO] self-bind SUCCESS: appliance %d bound to customer %s by customer self-service (token %s…)", appliance.ID, tok.CustomerID, hash[:8])
-	s.renderBind(w, http.StatusOK, bindPageData{State: "success"})
+	s.renderBind(w, http.StatusOK, bindPageData{State: "success", Lang: lang})
 }
 
 // bindPageHTML is the self-contained public page. It CANNOT link /style.css (that route is
@@ -220,12 +277,12 @@ func (s *Server) handleBind(w http.ResponseWriter, r *http.Request) {
 // surface, 2px radius, hairline rules, exception color for the failure banner. Hungarian, adult tone,
 // no emoji. It renders NO appliance data in any state.
 const bindPageHTML = `<!DOCTYPE html>
-<html lang="hu">
+<html lang="{{T "bind.htmllang"}}">
 <head>
 <meta charset="UTF-8">
 <meta name="viewport" content="width=device-width, initial-scale=1.0">
 <meta name="robots" content="noindex, nofollow">
-<title>Felhom — Doboz összekötése</title>
+<title>{{T "bind.title"}}</title>
 <style>
   :root { --navy:#0A2540; --ink:#0A2540; --muted:#5b6b7d; --line:#d8e0e8; --brand:#0083D8; --exc:#c0392b; --bg:#f4f7fa; }
   * { box-sizing: border-box; }
@@ -250,32 +307,32 @@ const bindPageHTML = `<!DOCTYPE html>
 <body>
 <div class="wrap">
   <div class="card">
-    <h1>Felhom <span>doboz</span> összekötése</h1>
+    <h1>{{T "bind.heading"}}</h1>
     {{if eq .State "form"}}
-      <p class="lead">Kösd össze a most telepített Felhom dobozodat a fiókoddal. Add meg a doboz képernyőjén látható párosító kódot és a tulajdonosi jelmondatodat.</p>
-      {{if .Failed}}<div class="banner">A megadott adatok nem megfelelőek. Ellenőrizd a párosító kódot és a tulajdonosi jelmondatot, majd próbáld újra.</div>{{end}}
+      <p class="lead">{{T "bind.lead"}}</p>
+      {{if .Failed}}<div class="banner">{{T "bind.failed"}}</div>{{end}}
       <form method="POST" action="/bind/{{.Token}}">
-        <label for="pairing_code">Párosító kód</label>
-        <input class="code" type="text" id="pairing_code" name="pairing_code" autocomplete="off" autocapitalize="characters" spellcheck="false" required autofocus placeholder="ABC-234">
-        <p class="hint">A doboz monitorán jelenik meg, a telepítés után.</p>
-        <label for="passphrase">Tulajdonosi jelmondat</label>
-        <input type="text" id="passphrase" name="passphrase" autocomplete="off" spellcheck="false" required placeholder="öt szó, kötőjellel vagy szóközzel">
-        <p class="hint">Az öt szóból álló kifejezés, amelyet a beállításkor kaptál. Ez igazolja, hogy a fiók a tiéd.</p>
-        <button type="submit">Összekötés</button>
+        <label for="pairing_code">{{T "bind.label.pairing"}}</label>
+        <input class="code" type="text" id="pairing_code" name="pairing_code" autocomplete="off" autocapitalize="characters" spellcheck="false" required autofocus placeholder="{{T "bind.placeholder.pairing"}}">
+        <p class="hint">{{T "bind.hint.pairing"}}</p>
+        <label for="passphrase">{{T "bind.label.passphrase"}}</label>
+        <input type="text" id="passphrase" name="passphrase" autocomplete="off" spellcheck="false" required placeholder="{{T "bind.placeholder.passphrase"}}">
+        <p class="hint">{{T "bind.hint.passphrase"}}</p>
+        <button type="submit">{{T "bind.submit"}}</button>
       </form>
-      <p class="note">Biztonsági okból 5 sikertelen próbálkozás után a hivatkozás zárolódik. Ilyenkor vedd fel a kapcsolatot az ügyfélszolgálattal.</p>
+      <p class="note">{{T "bind.note"}}</p>
     {{else if eq .State "success"}}
-      <p class="lead ok">Sikeres összekötés.</p>
-      <p>A doboz kb. egy percen belül folytatja a telepítést. Ezt az oldalt bezárhatod — a beállítás a háttérben befejeződik, és a vezérlőpultod hamarosan elérhető lesz.</p>
+      <p class="lead ok">{{T "bind.success.lead"}}</p>
+      <p>{{T "bind.success.body"}}</p>
     {{else if eq .State "consumed"}}
-      <p class="lead">Ez a hivatkozás már fel lett használva.</p>
-      <p>A doboz összekötése megtörtént. Ha úgy gondolod, hogy ez tévedés, vedd fel a kapcsolatot az ügyfélszolgálattal.</p>
+      <p class="lead">{{T "bind.consumed.lead"}}</p>
+      <p>{{T "bind.consumed.body"}}</p>
     {{else if eq .State "locked"}}
-      <p class="lead">Ez a hivatkozás zárolva van.</p>
-      <p>Túl sok sikertelen próbálkozás történt. Biztonsági okból a hivatkozás zárolódott — kérjük, vedd fel a kapcsolatot az ügyfélszolgálattal a doboz összekötéséhez.</p>
+      <p class="lead">{{T "bind.locked.lead"}}</p>
+      <p>{{T "bind.locked.body"}}</p>
     {{else}}
-      <p class="lead">Ez a hivatkozás érvénytelen vagy lejárt.</p>
-      <p>A hivatkozás 7 napig érvényes. Ha lejárt, kérj újat az ügyfélszolgálattól, vagy az összekötést az üzemeltető is elvégezheti.</p>
+      <p class="lead">{{T "bind.invalid.lead"}}</p>
+      <p>{{T "bind.invalid.body"}}</p>
     {{end}}
   </div>
   <p class="foot">Felhom.eu</p>