Swipes and a reader that will not scroll are reported (#384)

A swipe that only bounces sends no request and throws nothing, so
#383's stop at the 50th item left nothing in the log or the traces, and
the reader that would not scroll in the same report was never found.

The page now reports each swipe in the reader (next, prev, list, end,
short; a tap is not one) with where the reader stood, under the tap's
trace, and scroll_stuck when a drag up or down with room to move the
reader left it where it was. That one is watched by where the finger
was, not by what it landed on, so a layer lying over the reader is
caught, and its state names what is under the finger, what is inert,
the dialog, the reader's transform, a #dpeek left behind, and how long
since the app came back. ipx logs swipe as info and scroll_stuck as a
warning, in a new free-text state field, and the dashboard counts both.

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

web/CHANGELOG.md

@@ -24,6 +24,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- The page tells ipx what came of each swipe in the reader, and when a drag up or down would not scroll it, so a reader that stops responding can be found in the log (#384).
 - Caddy's own metrics, its requests and their times and the 502s ipx never sees, for Prometheus on a port of their own, `METRICS_BIND` (#371).
 - A tap or a key is its trace's root span: the page sends ipx when it began and when its last answer came, so Tempo shows how long it took beside the requests it made (#376).
 - Fonts of your choosing in Settings, beside the theme, kept by each browser as the theme is: one for the interface and one for reading an item's title and text, which is the interface's until chosen, with a little more room between the lines in a serif. Inter, your system's, the reading fonts Atkinson Hyperlegible, Lexend, Literata, Source Serif and OpenDyslexic, your device's serif, or monospace. The default keeps each theme's face as it was (#359).