refactor: rename marketplace to storefront across the entire monorepo

Comprehensive rename of all marketplace references to storefront:
- API module: apps/api/src/modules/marketplace/ → storefront/
- Components: MarketplaceHeader → StorefrontHeader, MarketplaceShell →
  StorefrontShell, MarketplaceFooter → StorefrontFooter
- Types: marketplace-homepage.ts → storefront-homepage.ts
- Test files: employee-marketplace-* → employee-storefront-*
- All source code identifiers, imports, route paths, and strings
- Documentation (docs/), CI config (.gitlab-ci.yml), scripts
- Dashboard, admin, storefront workspace references
- Prisma field names preserved (isListedOnMarketplace, marketplaceRating,
  marketplaceFunnelEvent) as they map to database schema

Validation:
- API type-check: 0 errors
- Storefront type-check: 0 errors
- Dashboard type-check: 0 errors
- Full monorepo type-check: only pre-existing admin TS18046

apps/api/src/lib/emailTranslations.test.ts

@@ -1,7 +1,7 @@
 import { describe, expect, it } from 'vitest'
 import {
   formatDate,
-  marketplaceReservationEmail,
+  storefrontReservationEmail,
   resetPasswordEmail,
   signupEmail,
 } from './emailTranslations'
@@ -40,8 +40,8 @@ describe('emailTranslations', () => {
     expect(html).toContain('45')
   })
 
-  it('includes optional contact phone in marketplace reservation HTML when present', () => {
-    const html = marketplaceReservationEmail.html({
+  it('includes optional contact phone in storefront reservation HTML when present', () => {
+    const html = storefrontReservationEmail.html({
       firstName: 'Yassine',
       vehicleYear: 2024,
       vehicleMake: 'Dacia',

apps/api/src/lib/emailTranslations.ts

@@ -117,9 +117,9 @@ export const resetPasswordEmail = {
   }, lang),
 }
 
-// ─── Marketplace reservation request ─────────────────────────────────────────
+// ─── Storefront reservation request ─────────────────────────────────────────
 
-export const marketplaceReservationEmail = {
+export const storefrontReservationEmail = {
   subject: (vehicleName: string, lang: Lang) => t({
     en: `Reservation Request Received — ${vehicleName}`,
     fr: `Demande de réservation reçue — ${vehicleName}`,