feat: add marketplace metrics, privacy features, and service registry endpoints

- Add Prometheus metrics for marketplace API throughput and error rates with new dashboard panels
- Implement confidential transaction models with encryption support and access control
- Add key management system with registration, rotation, and audit logging
- Create services and registry routers for service discovery and management
- Integrate ZK proof generation for privacy-preserving receipts
- Add metrics instru

docs/requirements.txt

@@ -0,0 +1,27 @@
+# MkDocs Material Theme
+mkdocs-material==9.4.8
+mkdocs-material-extensions==1.3.1
+
+# MkDocs Core and Plugins
+mkdocs==1.5.3
+mkdocs-git-revision-date-localized-plugin==1.2.6
+mkdocs-awesome-pages-plugin==2.9.2
+mkdocs-minify-plugin==0.7.4
+mkdocs-glightbox==0.3.4
+mkdocs-video==1.5.0
+mkdocs-social-plugin==1.0.0
+mkdocs-macros-plugin==1.0.5
+
+# Python Extensions for Markdown
+pymdown-extensions==10.8.1
+markdown-include==0.8.0
+mkdocs-mermaid2-plugin==1.1.1
+
+# Additional dependencies
+requests==2.31.0
+aiohttp==3.9.1
+python-dotenv==1.0.0
+
+# Development dependencies
+mkdocs-redirects==1.2.1
+mkdocs-monorepo-plugin==1.0.2