A more vivid orange for the logo's needle (#59)

The needle was #f7931e (#ff9f2e dark), a soft orange close enough in
lightness to the tallest blue bar that the two ran together where they
touch, and weak at favicon size. It is now #ff5500 (#ff6a1a on the dark
background), fully saturated and pushed towards red, away from the bars'
blue. favicon.png and apple-touch-icon.png are re-rendered from logo.svg.

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

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+
+- The logo's needle is a brighter, redder orange that stands apart from the blue bars.
+
 ### Fixed
 
 - On the Unread tab, a swipe back (or k) goes to the item you just read, instead of past it or