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/templates/app.html

@@ -44,8 +44,8 @@
     <a href="/?tab=new" class="tab-new {{if eq .Tab "new"}}active{{end}}"
        {{if eq .Tab "new"}}aria-current="page"{{end}}
        hx-get="/ui/list?tab=new" hx-target="#list" hx-swap="innerHTML"
-       hx-push-url="/?tab=new" hx-on::after-request="setActiveTab(this)">Updated{{if .NewCount}}
-      <span class="count">{{.NewCount}}</span>{{end}}</a>
+       hx-push-url="/?tab=new" hx-on::after-request="setActiveTab(this)">Updated
+      {{template "newcount" .}}</a>
     <a href="/?tab=fav" class="{{if eq .Tab "fav"}}active{{end}}"
        {{if eq .Tab "fav"}}aria-current="page"{{end}}
        hx-get="/ui/list?tab=fav" hx-target="#list" hx-swap="innerHTML"
@@ -61,26 +61,7 @@
   </nav>
   </div>
 
-  {{if .Recent}}
-  <section class="recent">
-    <h2>Continue reading</h2>
-    <div class="recent-strip">
-      {{range .Recent}}
-      <a class="recent-card {{if .HasNewChapter}}is-new{{end}}" href="{{.ContinueURL}}"
-         target="_blank" rel="noopener noreferrer">
-        <span class="recent-cover">
-          {{if .Cover}}<img src="{{.Cover}}" alt="" loading="lazy">
-          {{else}}<span class="monogram" aria-hidden="true">{{.Initial}}</span>{{end}}
-          {{if .HasNewChapter}}<span class="foot-rule"></span>
-          {{else if .Favorite}}<span class="foot-rule brass"></span>{{end}}
-        </span>
-        <span class="recent-title">{{.Title}}</span>
-        <span class="recent-chapter">{{.DisplayChapter}}{{if .HasNewChapter}} · New{{end}}</span>
-      </a>
-      {{end}}
-    </div>
-  </section>
-  {{end}}
+  {{template "recent" .}}
 
   <main id="list" class="list">
     {{template "list" .}}

backend/templates/chrome.html

@@ -0,0 +1,30 @@
+{{/* The two regions that live outside the swapped #list: the "Continue
+     reading" strip and the Updated badge. Both are rendered inline by app.html
+     and again, out of band, on every /ui/ response — a mutation must not leave
+     them describing the library as it was before the tap.
+
+     Both always render, hidden when they have nothing to say, so an out-of-band
+     swap always has an element with the right id to replace. */}}
+
+{{define "recent"}}
+<section class="recent" id="recent"{{if .OOB}} hx-swap-oob="true"{{end}}{{if not .Recent}} hidden{{end}}>
+  <h2>Continue reading</h2>
+  <div class="recent-strip">
+    {{range .Recent}}
+    <a class="recent-card {{if .HasNewChapter}}is-new{{end}}" href="{{.ContinueURL}}"
+       target="_blank" rel="noopener noreferrer">
+      <span class="recent-cover">
+        {{if .Cover}}<img src="{{.Cover}}" alt="" loading="lazy">
+        {{else}}<span class="monogram" aria-hidden="true">{{.Initial}}</span>{{end}}
+        {{if .HasNewChapter}}<span class="foot-rule"></span>
+        {{else if .Favorite}}<span class="foot-rule brass"></span>{{end}}
+      </span>
+      <span class="recent-title">{{.Title}}</span>
+      <span class="recent-chapter">{{.DisplayChapter}}{{if .HasNewChapter}} · New{{end}}</span>
+    </a>
+    {{end}}
+  </div>
+</section>
+{{end}}
+
+{{define "newcount"}}<span class="count" id="new-count"{{if .OOB}} hx-swap-oob="true"{{end}}{{if not .NewCount}} hidden{{end}}>{{.NewCount}}</span>{{end}}