Page: catch background fetches, no HTML in errors, a trace ends after a quiet minute (#219)

The page reported NetworkError rejections from the live update's list refresh and the first
feed load, which had no catch, whenever the network was gone (a laptop asleep). A Cloudflare
502 page became a request's error message, since api() used whatever body came back. And
the trace id lived until the next tap, so background requests nine hours apart shared one
trace. The id now ends after a minute without a request; a play's position saves, every ten
seconds, keep it going.

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

web/CHANGELOG.md

@@ -11,6 +11,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+
+- A live update or a list refresh that fails because the network is gone (a laptop asleep) is no longer reported as an error, an error page from Cloudflare no longer becomes a request's message, and requests a minute or more after a tap start a trace of their own instead of joining that tap's (#219).
+
 ## [1.0.0] - 2026-10-12
 
 ### Added