Run the top bar's colour up behind the Dynamic Island on iOS 26 (#147)

46f9370 set theme-color, but Safari 26 ignores it. iOS 26 paints the strip behind the status bar
and the island in the background colour of a sticky or fixed element at the page's top edge, and
failing that the root's. The top bar was neither, and the root had no colour of its own (only
body did), so iOS used black or white: a band of another colour above the bar.

The bar is sticky now, though nothing scrolls under it, so iOS reads its colour; the root has the
page's background for screens with nothing at the top edge; Classic's metal bar gets a colour
under its gradient, the top of the metal, since iOS reads no gradient. theme-color stays, set to
the bar's colour, for iPhones before iOS 26 and for Android. Glass's bar is see-through, so iOS
frosts what is under it there, as the bar itself does.

Taken from developers' reports of iOS 26, not Apple's documentation, and not yet seen on a phone.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

CHANGELOG.md

@@ -14,7 +14,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
-- On an iPhone, the bar around the Dynamic Island is the theme's background, not the system's own black or white.
+- On an iPhone, the top bar's colour runs all the way up behind the status bar and the Dynamic Island, with no band of another colour above it.
 - A feed's buttons stay on one row on a narrow phone, and the reader's buttons stay together instead of breaking across lines under a long feed name.
 - A moment's DNS failure no longer marks a feed as failing for a day or calls it gone: iPX tries it again in ten minutes. One failed lookup one morning left 205 podcasts unread, uncategorised and labelled gone until the next day. A name that does not resolve is said to be maybe gone, and only once it has been failing a day, on its Directory page as on its own.