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.

.dockerignore

@@ -0,0 +1,44 @@
+# Git
+.git
+.gitignore
+
+# Node
+node_modules
+npm-debug.log
+dist
+build
+
+# Python
+__pycache__
+*.pyc
+*.pyo
+*.pyd
+.Python
+env
+venv
+.venv
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Docker
+docker-compose.yml
+Dockerfile*
+.dockerignore
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Project specific
+Log
+Log_from_docker
+tmp
+output
+*.md
+# Allow these txt files
+!gemini_api_key.txt
+!serpapikey.txt
+!market-intel.requirements.txt
+!b2b-marketing-assistant/requirements.txt
+!requirements.txt
+