- Configurable via 'ALLOWED_IFRAME_SOURCES' .env option. - Also updated how CSP rules are set, with a single header being used instead of many. - Also applied CSP rules to HTML export outputs. - Updated tests to cover. For #3314
As per guidance from google's CSP evaluator.
- Added caching for custom html head parsing to add nonce. - Also moved api docs page into web routes to prevent issues.