Refresh buttons turn from the press to the end of their scan; quick checks keep the count (#232, #233)

The buttons followed the feeds being checked, so they stopped between one feed and the next;
7ecbe82 held them for 600 ms over each gap. Now pressing one starts it, and scan_done stops
it only when it is the end of the scan asked for: scan_done carries `only` and `forced`, so a
scheduled scan finishing first does not stop a button whose scan is queued behind it. An
error event, a job that failed without a scan_done, stops them all.

A row's spinner stood in for its unread count from the moment its feed was checked; most
checks take milliseconds, so each count blinked as the scan went by. It now waits 300 ms.

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

web/CHANGELOG.md

@@ -13,7 +13,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
-- The check-every-feed button turns smoothly through a scan instead of jerking back upright between one feed and the next (#231).
+- The refresh buttons turn from the moment they are pressed until the scan they asked for has finished, smoothly, instead of jerking back upright between one feed and the next (#231, #233).
+- A feed's unread count stays put while a scan checks it quickly; the spinner takes its place only when a check takes a moment (#232).
 
 ## [1.0.1] - 2026-10-13