- Updated ProxyFix configuration to handle all proxy headers (x_for, x_proto, x_host, x_port, x_prefix)
- Added template context processor to inject script_root and url_root into all templates
- Created JavaScript helper functions in base template for proxy-aware URL generation:
  - buildUrl() - Build URLs with correct proxy prefix
  - proxyFetch() - Make fetch requests with proxy-aware URLs
  - navigateTo() - Navigate to URLs with proxy prefix
  - getCurrentUrl() - Get current URL with proxy prefix
  - buildUrlWithParams() - Build URLs with query parameters
- Updated all templates with hardcoded JavaScript URLs to use proxyFetch():
  - admin_settings.html
  - admin_users.html
  - admin_migrations.html
  - match_detail.html
  - fixture_detail.html
  - upload/zip.html
  - user_tokens.html
- Updated templates with window.location.href to use navigateTo():
  - clients.html
  - reports.html
  - client_report_detail.html
- Updated templates using window.location.href for URL manipulation to use getCurrentUrl():
  - match_report_detail.html
  - bet_detail.html
  - reports.html
  - client_report_detail.html
- Created PROXY_SUPPORT.md documentation file

This implementation ensures all URLs generated and managed in the web dashboard correctly handle the root path when behind an nginx proxy with X-Forwarded-Prefix header (e.g., /mbetterc).