feat(i18n): add scripts for locale translation and patching

- Implemented `fill-de-extended-gaps.js` to fill missing billing/orders keys in de-extended from de.
- Created `fill-i18n-deep.py` for deep translation of locale JSONs using deep-translator with fallback options.
- Added `fill-i18n-locales.js` to translate locale JSONs and write overrides for untranslated keys.
- Introduced `fix-en-leaks.py` to translate keys that still match the en-US merge, addressing English leaks.
- Developed `patch-de-ch-swiss.js` to replace 'ß' with 'ss' in de-CH.json without deleting existing entries.
- Created `patch-en-gb-au.js` to apply UK/AU spelling corrections in en-GB and en-AU locales.
- Added shell scripts `run-fix-en-leaks.sh` and `run-i18n-deep-fill.sh` for sequential execution of translation tasks.
- Implemented `update-i18n-todo-stats.js` to update statistics in the I18N_TODO.md file based on translation completeness.

frontend/package.json

@@ -7,7 +7,13 @@
     "build": "vite build",
     "serve": "vite preview",
     "i18n:audit": "node scripts/audit-i18n.js",
-    "i18n:status": "node scripts/translation-status.js"
+    "i18n:status": "node scripts/translation-status.js",
+    "i18n:fill": "node ../scripts/fill-i18n-locales.js --all --delay 500",
+    "i18n:fill:deep": "PYTHONUNBUFFERED=1 ../scripts/.venv-i18n/bin/python -u ../scripts/fill-i18n-deep.py --all --delay 0.2",
+    "i18n:fix-leaks": "PYTHONUNBUFFERED=1 ../scripts/.venv-i18n/bin/python -u ../scripts/fix-en-leaks.py",
+    "i18n:fix-leaks:all": "bash ../scripts/run-fix-en-leaks.sh",
+    "i18n:completeness": "node ../scripts/check-i18n-completeness.js",
+    "i18n:update-todo": "node ../scripts/update-i18n-todo-stats.js"
   },
   "dependencies": {
     "axios": "^1.7.3",
@@ -27,6 +33,7 @@
     "vuex": "^4.1.0"
   },
   "devDependencies": {
+    "@vitalets/google-translate-api": "^9.2.1",
     "@vitejs/plugin-vue": "^6.0.2",
     "eslint": "^9.39.1",
     "eslint-plugin-vue": "^9.0.0",