build-frontend: drop --localize, drop en-US promotion step

We never translated any ordpool components and the locale switcher is
hidden in the footer, so multi-locale builds produce 30+ duplicate
bundles for nothing. Single-locale build is faster and the dist root
ends up with index.html directly (no en-US/ subdir to promote).

Author: hans-crypto

.github/workflows/build-frontend.yml

@@ -25,14 +25,10 @@ jobs:
       working-directory: frontend
       run: npm ci
 
-    - name: Build (production, --localize)
+    - name: Build (production, single English locale — we never translated ordpool components)
       working-directory: frontend
       run: npm run build
 
-    - name: Promote en-US to root (Pages serves the root)
-      working-directory: frontend
-      run: mv dist/mempool/browser/en-US/* dist/mempool/browser/
-
     - name: Sanity-check the deploy artifact
       working-directory: frontend
       run: |

frontend/package.json

@@ -32,7 +32,7 @@
     "start:local-esplora": "npm run generate-themes && npm run generate-config && npm run sync-assets-dev && npm run ng -- serve -c local-esplora",
     "start:local-prod": "npm run generate-themes && npm run generate-config && npm run sync-assets-dev && npm run ng -- serve -c local-prod",
     "start:mixed": "npm run generate-themes && npm run generate-config && npm run sync-assets-dev && npm run ng -- serve -c mixed",
-    "build": "npm run generate-themes && npm run generate-config && npm run ng -- build --configuration production --localize && npm run sync-assets-dev && npm run sync-assets",
+    "build": "npm run generate-themes && npm run generate-config && npm run ng -- build --configuration production && npm run sync-assets-dev && npm run sync-assets",
     "generate-themes": "node generate-themes.js",
     "copy-themes": "node generate-themes.js copy",
     "sync-assets": "npm run copy-themes && rsync -av ./src/resources ./dist/mempool/browser && node sync-assets.js 'dist/mempool/browser/resources/'",