chore: bulk commit of pre-existing changes

Includes:
- Admin dashboard layout and page updates
- API account auth module (routes, schemas, service)
- Dashboard sign-up form extraction, middleware refactor
- Marketplace proxy and middleware updates
- CORS origins expansion for dev environment
- Seed email domain correction (.com → .ma)
- Docs: create-account guide, fleet page, signup plan
- Various UI component and layout refinements

apps/marketplace/next.config.js

@@ -1,11 +1,15 @@
 /** @type {import('next').NextConfig} */
 
-const { buildSecurityHeaders } = require('../../config/nextSecurityHeaders')
+const { buildSecurityHeaders, normalizeAssetPrefix } = require('../../config/nextSecurityHeaders')
 
 // The marketplace proxies /dashboard and /admin to their own Next dev servers.
 // Allow those asset-prefix origins so proxied pages can load chunks and HMR.
+const dashboardAssetSource = normalizeAssetPrefix(
+  process.env.DASHBOARD_ASSET_PREFIX ?? (process.env.NODE_ENV !== 'production' ? 'http://localhost:3001' : undefined),
+  '/dashboard',
+)
 const securityHeaders = buildSecurityHeaders({
-  assetSources: [process.env.DASHBOARD_ASSET_PREFIX, process.env.ADMIN_ASSET_PREFIX],
+  assetSources: [dashboardAssetSource, process.env.ADMIN_ASSET_PREFIX],
 })
 const nextConfig = {
   images: {
@@ -25,11 +29,27 @@ const nextConfig = {
       },
     ]
   },
+  async redirects() {
+    return [
+      {
+        source: '/dashboard/dashboard',
+        destination: '/dashboard',
+        permanent: false,
+      },
+      {
+        source: '/dashboard/dashboard/:path*',
+        destination: '/dashboard/:path*',
+        permanent: false,
+      },
+    ]
+  },
   async rewrites() {
     const dashboardOrigin = process.env.DASHBOARD_INTERNAL_URL ?? 'http://dashboard:3001'
     const adminOrigin = process.env.ADMIN_INTERNAL_URL ?? 'http://admin:3002'
 
     return [
+      // Dashboard has basePath '/dashboard'. The proxy preserves the prefix
+      // so the dashboard can strip it and route internally.
       {
         source: '/dashboard',
         destination: `${dashboardOrigin}/dashboard`,
@@ -38,6 +58,7 @@ const nextConfig = {
         source: '/dashboard/:path*',
         destination: `${dashboardOrigin}/dashboard/:path*`,
       },
+      // Admin routes (also uses basePath)
       {
         source: '/admin',
         destination: `${adminOrigin}/admin`,