The paginator renders inside a sandboxed iframe that blocks @font-face
URL fetches. Fonts were never loading — all font-family rules fell back
to the generic 'serif' system font, making every reading font identical.
Fix: fetch font files on the parent page, create blob: URLs via
URL.createObjectURL(), and use those blob URLs in the @font-face rules
injected into the iframe via setStyles(). Blob URLs are always
same-origin with the creating document, so the sandboxed iframe can
access them with allow-same-origin.
Also added Playwrite NZ Guides as a test font for verifying font
switching works.
john-okeefe
9ca8e2aa44