Remove legacy references and clean up for NHSDigital migration

- Update all package references from fergusbisset to @nhsdigital/fdp-design-system
- Update GitHub URLs to NHSDigital/fdp-react-design-system
- Update docs/PUBLISHING.md for npm public registry
- Update docs/RELEASE_v0.0.43.md installation instructions
- Add ssr-analysis-report/ to .gitignore and remove from tracking
- Rebuild dist/ with updated references

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: fergusbisset

.gitignore

@@ -51,3 +51,6 @@ Thumbs.db
 .env.test.local
 .env.production.local
 dist-dev/
+
+# Generated reports
+ssr-analysis-report/