feat(portal): complete masterplan with deterministic budget simulator, RAG assistant, agency cross-tenant view and multi-tenant middleware

src/middleware.ts

@@ -0,0 +1,43 @@
+import { NextRequest, NextResponse } from 'next/server';
+
+export function middleware(req: NextRequest) {
+  const url = req.nextUrl.clone();
+  const hostname = req.headers.get('host') || '';
+
+  // 1. Extraer slug desde subdominio (ej: acme.4ventures.es)
+  let tenantSlug = '4ventures-hub';
+  const parts = hostname.split('.');
+
+  if (parts.length > 2) {
+    const sub = parts[0].toLowerCase();
+    if (sub !== 'app' && sub !== 'git' && sub !== 'supabase' && sub !== 'n8n' && sub !== 'www') {
+      tenantSlug = sub;
+    }
+  }
+
+  // 2. Override opcional vía query param ?tenant=slug
+  const queryTenant = url.searchParams.get('tenant');
+  if (queryTenant) {
+    tenantSlug = queryTenant.toLowerCase();
+  } else {
+    const cookieTenant = req.cookies.get('4v_tenant')?.value;
+    if (cookieTenant) {
+      tenantSlug = cookieTenant;
+    }
+  }
+
+  const response = NextResponse.next({
+    request: {
+      headers: new Headers(req.headers)
+    }
+  });
+
+  response.headers.set('x-tenant-slug', tenantSlug);
+  response.cookies.set('4v_tenant', tenantSlug, { path: '/', maxAge: 60 * 60 * 24 * 30 });
+
+  return response;
+}
+
+export const config = {
+  matcher: ['/((?!_next/static|_next/image|favicon.ico|_4v_attr.js).*)']
+};