feat: multi-module improvements across merchant, store, i18n, and customer systems

- Fix platform-grouped merchant sidebar menu with core items at root level
- Add merchant store management (detail page, create store, team page)
- Fix store settings 500 error by removing dead stripe/API tab
- Move onboarding translations to module-owned locale files
- Fix onboarding banner i18n with server-side rendering + context inheritance
- Refactor login language selectors to use languageSelector() function (LANG-002)
- Move HTTPException handling to global exception handler in merchant routes (API-003)
- Add language selector to all login pages and portal headers
- Fix customer module: drop order stats from customer model, add to orders module
- Fix admin menu config visibility for super admin platform context
- Fix storefront auth and layout issues
- Add missing i18n translations for onboarding steps (en/fr/de/lb)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docs/deployment/hetzner-server-setup.md

@@ -2415,7 +2415,7 @@ No push notifications needed — Google syncs object changes automatically.
 After Google Wallet is verified working:
 
 1. **Submit for Google production approval** — required before non-test users can add passes
-2. **Apple Wallet** — separate setup requiring Apple Developer account, APNs certificates, and pass signing certificates (see [Loyalty Module docs](../modules/loyalty.md#apple-wallet))
+2. **Apple Wallet** — separate setup requiring Apple Developer account, APNs certificates, and pass signing certificates (see [Loyalty Module docs](../modules/loyalty/index.md#configuration))
 
 ---