Refresh the strip and the badge out of band

The "Continue reading" strip and the Updated badge describe the whole library
but live outside the #list htmx swaps, so nothing corrected them after a
mutation: archiving a series left it sitting in the strip under "Continue
reading", with the badge still counting it. A tab switch had the same problem
from the other side — the strip was server-gated to All but could not be
re-rendered client-side, so /?tab=all reached by htmx and the same URL reloaded
produced different DOM.

Both regions move into chrome.html and always render, hidden when they have
nothing to say, so an out-of-band swap always has an id to target. /ui/list and
every mutation append them; the tab the reader is on comes from HX-Current-URL.
filter.js keeps only the job the server cannot do — hiding the strip while a
filter is active.

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

backend/static/filter.js

@@ -14,13 +14,13 @@
       if (!card.hidden) visible++;
     });
 
-    // The strip is All-only and never filtered. It lives outside #list, so an
-    // htmx tab switch does not re-render it and this is what takes it down;
-    // leaving it up during a search would also put non-matching covers above
-    // an empty list.
+    // The server decides what the strip holds — it ships empty for every tab
+    // but All, and out of band after every mutation. All this has to do is keep
+    // it down while a filter is active, since the strip is never filtered and
+    // would otherwise put non-matching covers above an empty list.
     var recent = document.querySelector(".recent");
     if (recent) {
-      recent.hidden = needle !== "" || !document.querySelector('.tabs a.active[href="/?tab=all"]');
+      recent.hidden = needle !== "" || !recent.querySelector(".recent-card");
     }
 
     // An empty bucket already explains itself server-side; this only speaks