Release v26.5.1

Bundled PDF.js: 6.4.299 (unchanged).

Fixed

• Safari and iOS older than 18.4 couldn't start the viewer
  (#457). PDF.js 6.4.299 touches
  the Iterator global as soon as it loads, so on those versions the page stayed on
  "Loading PDF...". The polyfills injected into the bundled PDF.js now add the iterator
  helpers, AbortSignal.any() and async iteration of ReadableStream, which covers Safari
  and iOS 17 and 18.0 to 18.3.
• On Safari and iOS 17.0 to 17.3, pages kept their loading spinner and never drew. The PDF.js
  worker packs every font with ArrayBuffer.prototype.transferToFixedLength() (Safari 17.4),
  so no font reached the page; it's polyfilled now.
• On Safari and iOS older than 17.5 the toolbar icons were invisible and fields and menus lost
  their colours, because PDF.js sets them with CSS light-dark(). The build now appends plain
  fallback values for PDF.js's top-level colour variables, used only by browsers without
  light-dark() and following the component's theme. Some sidebar and dialog colours there
  still fall back to browser defaults.
• On Safari and iOS 17.0 and 17.1, pages were drawn about three times too large and cut off, and
  zooming or scrolling never showed the rest. PDF.js writes its stylesheet with CSS nesting, and
  those versions drop a nested rule that starts with an element name (Safari 17.2 relaxed that),
  including the one that fits each page's canvas to its box. The build now flattens the nesting
  in viewer.css, which also adds -webkit-backdrop-filter for Safari before 18.
• A numeric zoom set before the document's first view came out 100 times too small: "1.4"
  showed the page at 1.4% instead of 140%. PDF.js reads its initial zoom as a percentage, while
  zoom and zoomChange use scale factors, so an app that saved zoomChange and set it again
  on the next document lost the page. The value is now converted on that path. Thanks to
  @jhthompson for the fix. (#459)
• When PDF.js can't start at all, the loading spinner no longer runs forever. That happens on
  Safari and iOS 16 or older (no build of PDF.js 6.x supports them, Mozilla's legacy build
  included) or when a viewer file fails to load. The component now stops loading and fires
  onDocumentError with name: 'UnsupportedBrowser' or name: 'ViewerLoadError', so the
  app decides what its users see.

Added

• customErrorTpl templates receive errorName alongside errorMessage and errorClass, so
  a template can show its own message for an unsupported browser.

Docs

• Error-Display-Examples.md described built-in error templates (errorTemplate="basic" and
  others) that were deprecated in 25.0.0 and are no longer in the package, and its custom
  template example read a context variable that doesn't exist. It now documents
  customErrorTpl as it works. Several docs-site examples left out [errorOverride]="true",
  without which customErrorTpl never shows.