Consolidate tools into a secure Docker architecture with landing page

- Implement a central reverse proxy (Nginx) with Basic Auth on port 8090.
- Create a unified landing page (dashboard) to access B2B Assistant and Market Intelligence.
- Update frontends with relative API paths and base paths for subdirectory routing (/b2b/, /market/).
- Optimize Docker builds with .dockerignore and a Python-based image for market-backend.
- Enable code sideloading for Python logic via Docker volumes.
- Fix TypeScript errors in general-market-intelligence regarding ImportMeta.

general-market-intelligence/nginx.conf

@@ -10,9 +10,9 @@ server {
 
     # 2. Proxy API Requests to Backend Container
     location /api/ {
-        # 'backend' is the service name in docker-compose.yml
+        # 'market-backend' is the service name in docker-compose.yml
         # Port 3001 is where the Node.js bridge listens
-        proxy_pass http://backend:3001/api/;
+        proxy_pass http://market-backend:3001/api/;
         proxy_http_version 1.1;
         proxy_set_header Upgrade $http_upgrade;
         proxy_set_header Connection 'upgrade';