feat(legal): bilingual (RU + EN) legal pages with a language + theme switcher

Add English versions of the privacy policy, EULA and offer (ui/legal/*_en.md) and render each legal page as one self-contained bilingual document: both language bodies plus a header language toggle and theme toggle (no back), a small inline ES5 script that switches language client-side (no reload, default Russian + persisted) and applies the theme (system default + persisted override) — mirroring the landing. The offer's English view transliterates the Russian product names spliced from the live catalog.

renderLegalHtml now takes both language sources; renderOffer splices the price list into both; the renderer bakes and reads the _en sources and pre-renders the static pages at boot. Also wrap the /offer/ contour probe in the same retry+timeout as the legal probe (the offer page is now bilingual and larger). Docs + renderer/ui tests updated.

.gitea/workflows/ci.yaml

@@ -522,10 +522,21 @@ jobs:
           # (the seller INN, §11) AND that the pricing marker was substituted (proves the fetch +
           # splice ran), never just the status. Data-independent: an empty catalog still substitutes
           # the marker with nothing, so "pricing_template" must be absent either way.
-          out="$(docker run --rm --network edge alpine:3.20 wget -q -O - http://scrabble/offer/ 2>&1 || true)"
-          if echo "$out" | grep -q "290210610742" && ! echo "$out" | grep -q "pricing_template"; then
-            echo "ok: /offer/ serves the rendered offer with the price list spliced in"
-          else
+          # Full body is needed (the INN is in §11 and the marker check spans the page), so this
+          # cannot be a head-only probe like the legal one. Retry with a timeout instead: the offer is
+          # now bilingual (RU + EN, larger), and a single-shot fetch can race the renderer's restart in
+          # the same deploy.
+          ok=
+          for i in $(seq 1 20); do
+            out="$(docker run --rm --network edge alpine:3.20 wget -q -T 10 -O - http://scrabble/offer/ 2>&1 || true)"
+            if echo "$out" | grep -q "290210610742" && ! echo "$out" | grep -q "pricing_template"; then
+              echo "ok: /offer/ serves the rendered offer with the price list spliced in"
+              ok=1
+              break
+            fi
+            sleep 3
+          done
+          if [ -z "$ok" ]; then
             echo "FAIL: /offer/ did not serve the rendered offer (route fell through, or the price splice failed)"
             docker logs --tail 50 scrabble-renderer || true
             docker logs --tail 50 scrabble-backend || true