A spinner on the feed being checked, not toasts; check only your own feeds

The scan's events reach everyone, so every browser showed "<feed>: N new" and
"Scanning…" toasts, and refreshed, for everyone's feeds. Now a feed's row, and
its folder's, carries a spinner between feed_start and its done, skip or error;
the list refreshes only for the reader's own feeds; the scan toasts are gone, and
"Downloaded" is said only for a file on screen.

"Check every feed" from the web UI sent a scan of every feed on the server.
Command::Fetch takes an optional `feeds` list -- those feeds and the feeds
inside any OPML among them -- and the web fills it with the asker's
subscriptions. The schedule and the CLI send none, meaning every feed.

Closes #37.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

web/src/gestures.ts

@@ -34,7 +34,6 @@ function pullShow(dy: number){
 function refreshFeed(){
   const f = S.feeds.find(x => x.id === S.feed);
   if(!f && S.feed !== ':all') return;
-  toast(f ? `Checking ${f.title || f.id} for new items…` : 'Checking every feed for new items…');
   // New items arrive by the event stream when the scan finishes, as they do for a button press.
   api('/api/fetch', {method: 'POST', body: JSON.stringify(f ? {feed: f.id, force: true} : {force: true})})
     .catch(e => toast(e.message, true));