v0.249.0: i18n slice 1 release B — backup pages in English, Hungarian byte-identical (R-556)

Seven backup pages + the restore-progress JS converted against fixtures captured unconverted
(f8ebc47); recovery renders through executeTemplateLang; English retrieval claims registered;
the Fut comparison left unconverted (R-563).

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

controller/internal/web/server.go

@@ -5,6 +5,7 @@ import (
 	"context"
 	"fmt"
 	"html/template"
+	"io"
 	"io/fs"
 	"log"
 	"net/http"
@@ -869,6 +870,19 @@ func (s *Server) executeTemplate(w http.ResponseWriter, r *http.Request, name st
 	buf.WriteTo(w)
 }
 
+// executeTemplateLang renders a page that stands OUTSIDE the dashboard chrome — sign-in, claim,
+// recovery, the guest share pages, the catch-all — in the request's language (slice 1, R-556).
+// Deliberately NOT executeTemplate: that one injects the session CSRF fields and the escrow reminder bar
+// (R-543), which a guest or a signed-out visitor must never receive. It only picks the language set and
+// tells the page which language it is in. The caller keeps its own headers and error handling.
+func (s *Server) executeTemplateLang(w io.Writer, r *http.Request, name string, data map[string]interface{}) error {
+	lang := s.langFor(r)
+	if data != nil {
+		data["Lang"] = lang
+	}
+	return s.templatesFor(lang).ExecuteTemplate(w, name, data)
+}
+
 // --- Static file / asset serving ---
 
 func (s *Server) serveCSSHandler(w http.ResponseWriter, r *http.Request) {