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/app.ts

@@ -28,7 +28,7 @@ import customersRouter     from './modules/customers/customer.routes'
 import vehiclesRouter      from './modules/vehicles/vehicle.routes'
 import companiesRouter     from './modules/companies/company.routes'
 import reservationsRouter  from './modules/reservations/reservation.routes'
-import marketplaceRouter   from './modules/marketplace/marketplace.routes'
+import storefrontRouter   from './modules/storefront/storefront.routes'
 import siteRouter          from './modules/site/site.routes'
 import reviewsRouter       from './modules/reviews/review.routes'
 import complaintsRouter    from './modules/complaints/complaint.routes'
@@ -95,8 +95,8 @@ const routeDocs = [
   { method: 'GET',  path: `${v1}/analytics/dashboard`,       description: 'Dashboard analytics' },
   { method: 'GET',  path: `${v1}/analytics/report`,          description: 'Analytics report' },
   { method: 'GET',  path: `${v1}/notifications/company`,     description: 'Company notifications' },
-  { method: 'GET',  path: `${v1}/marketplace/cities`,        description: 'Marketplace cities' },
-  { method: 'GET',  path: `${v1}/marketplace/search`,        description: 'Marketplace search' },
+  { method: 'GET',  path: `${v1}/storefront/cities`,        description: 'Storefront cities' },
+  { method: 'GET',  path: `${v1}/storefront/search`,        description: 'Storefront search' },
   { method: 'GET',  path: `${v1}/site/:slug/brand`,          description: 'Public site brand config' },
   { method: 'GET',  path: `${v1}/companies/me`,              description: 'Current company profile' },
   { method: 'GET',  path: `${v1}/subscriptions/plans`,       description: 'Subscription plans' },
@@ -187,7 +187,7 @@ export function createApp() {
   app.use(`${v1}/admin/auth`,     authLimiter)
   app.use(`${v1}/admin`,          adminLimiter, adminRouter)
 
-  app.use(`${v1}/marketplace`,    publicLimiter, marketplaceRouter)
+  app.use(`${v1}/storefront`,    publicLimiter, storefrontRouter)
   app.use(`${v1}/site`,           publicLimiter, siteRouter)
   app.use(`${v1}/subscriptions`,  subscriptionPublicRouter)
   app.use(`${v1}/subscriptions`,  subscriptionWebhookRouter)