diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9077250..a9ca53e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,16 @@ Follows [Keep a Changelog](https://keepachangelog.com/en/1.0.0/) · versioned wi
 
 ---
 
+## [1.13.5] — 2026-07-06
+
+### Added
+- **Search + sort in the Casting sidebar** ("Characters found") — filter by name and sort by line count or alphabetically, matching the same controls added to the Library's character list.
+
+### Fixed
+- **Merging characters could freeze the page long enough to trigger the browser's "Page Unresponsive" dialog** — the merge itself is a fast array loop, but redrawing the whole feed afterward (thousands of DOM rows, each running the highlight regex pass) was one long synchronous block. A spinner overlay alone couldn't fix this — it would freeze right along with everything else in the same JS turn. The redraw is now chunked across animation frames with a real, moving progress bar, so the browser stays responsive and the merge no longer looks like a crash on a large book.
+
+---
+
 ## [1.13.4] — 2026-07-06
 
 ### Added
diff --git a/VERSION b/VERSION
index 80138e7..43ded90 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.13.4
+1.13.5
diff --git a/static/index.html b/static/index.html
index 663f433..4f3f150 100644
--- a/static/index.html
+++ b/static/index.html
@@ -10,7 +10,7 @@
   <meta name="format-detection" content="telephone=no">
   <meta name="color-scheme" content="light dark">
   <meta name="theme-color" content="#2563EB">
-  <meta name="app-version" content="1.13.4">
+  <meta name="app-version" content="1.13.5">
   <link rel="manifest" href="/manifest.webmanifest">
   <link rel="icon" href="/static/icon.svg" type="image/svg+xml">
   <link rel="apple-touch-icon" href="/static/icon.svg">
@@ -27,7 +27,7 @@
 
   <!-- ── Core styles (local — no CDN dependency for first paint) ────────── -->
   <link rel="stylesheet" href="/static/vendor/mdi/materialdesignicons.min.css">
-  <link rel="stylesheet" href="/static/style.css?v=1.13.4">
+  <link rel="stylesheet" href="/static/style.css?v=1.13.5">
 
 
   <!-- ── Flag icons — non-blocking (loaded async, icons appear after JS) ── -->
@@ -365,7 +365,7 @@ window.toggleNavTree = function(treeId, chevronId) {
 </script>
 
 <!-- loader.js: fetches sections → loads JS modules → removes skeleton -->
-<script src="/static/loader.js?v=1.13.4"></script>
+<script src="/static/loader.js?v=1.13.5"></script>
 
 </body>
 </html>
diff --git a/static/js/audiobook.js b/static/js/audiobook.js
index 656679c..d2c312e 100644
--- a/static/js/audiobook.js
+++ b/static/js/audiobook.js
@@ -1015,6 +1015,30 @@ function highlightText(text, names) {
 // Small dropdown anchored to the "Recast options" caret next to "View
 // Characters", once a book's already been cast before — offers the existing
 // full recast plus a targeted "recast just these characters" flow.
+// Lightweight "working on it" overlay for operations that block the main
+// thread for a noticeable moment (e.g. rewriting + redrawing thousands of
+// segments on a character merge) — without this, a long synchronous chunk
+// of work just makes the page stop responding with no visible cause, which
+// reads as a crash rather than "still working". Returns the overlay element;
+// call .remove() on it when the work finishes.
+function _abShowBusyOverlay(message, withProgress) {
+  const ov = document.createElement('div');
+  ov.className = 'audiobook-overlay ab-busy-overlay';
+  ov.innerHTML = `<div class="audiobook-box" style="text-align:center;">
+    <span class="mdi mdi-loading mdi-spin" style="font-size:28px; color:var(--accent);"></span>
+    <div class="audiobook-msg ab-busy-msg" style="margin:12px 0 0;">${escHtml(message)}</div>
+    ${withProgress ? '<div class="reader-synth-track" style="margin-top:10px"><div class="reader-synth-fill ab-busy-fill" style="width:0%"></div></div>' : ''}
+  </div>`;
+  document.body.appendChild(ov);
+  ov.setProgress = (done, total) => {
+    const fill = ov.querySelector('.ab-busy-fill');
+    if (fill && total) fill.style.width = Math.round((done / total) * 100) + '%';
+    const msgEl = ov.querySelector('.ab-busy-msg');
+    if (msgEl) msgEl.textContent = `${message} (${done} / ${total})`;
+  };
+  return ov;
+}
+
 function _abOpenRecastCharsMenu(anchorEl, bookTitle, existingChars) {
   document.querySelectorAll('.ab-recast-menu').forEach(el => el.remove());
   const menu = document.createElement('div');
@@ -1145,6 +1169,13 @@ function audiobookCastView(total, llmUrl, defaultModel, isIdle = false) {
           <span class="ab-cv-side-title">Characters found</span>
           <button class="ab-cv-side-collapse" id="ab-cv-side-collapse" type="button" title="Collapse to avatars"><span class="mdi mdi-chevron-left"></span></button>
         </div>
+        <div class="ab-cv-side-tools">
+          <input type="text" class="ab-cv-side-search" id="ab-cv-side-search" placeholder="Search characters…" autocomplete="off">
+          <select class="ab-cv-side-sort" id="ab-cv-side-sort" title="Sort">
+            <option value="count">Lines</option>
+            <option value="alpha">A–Z</option>
+          </select>
+        </div>
         <div class="ab-cv-chars" id="ab-cv-chars">
           <div class="ab-skel-chars">
             ${[38,62,45,28,54,35].map(w => `<div class="ab-skel-char-row"><div class="ab-skel-dot"></div><div class="ab-skel-line" style="width:${w}%"></div><div class="ab-skel-num"></div></div>`).join('')}
@@ -1932,9 +1963,13 @@ STRIKTE FORMAT- UND TEXTREGELN:
     inp.addEventListener('keydown', e => { if (e.key === 'Enter') { e.preventDefault(); _doSearch(true); } });
   };
 
+  let _abRosterFilter = '';
+  let _abRosterSort = 'count';
   const renderRoster = () => {
-    const items = [...roster.entries()].filter(([, info]) => info.count > 0).sort((a, b) => b[1].count - a[1].count);
-    if (!items.length) { chars.innerHTML = '<span class="ab-cv-empty">reading…</span>'; return; }
+    const q = _abRosterFilter.trim().toLowerCase();
+    let items = [...roster.entries()].filter(([n, info]) => info.count > 0 && (!q || n.toLowerCase().includes(q)));
+    items.sort(_abRosterSort === 'alpha' ? (a, b) => a[0].localeCompare(b[0]) : (a, b) => b[1].count - a[1].count);
+    if (!items.length) { chars.innerHTML = `<span class="ab-cv-empty">${q ? 'No matches' : 'reading…'}</span>`; return; }
     const prev = _abBar.hidden ? null : _abBar.dataset.charName;
     chars.innerHTML = items.map(([n, info]) => {
       const color = info.color || colorFor(n);
@@ -1953,6 +1988,23 @@ STRIKTE FORMAT- UND TEXTREGELN:
     });
   };
 
+  (() => {
+    const searchInp = panel.querySelector('#ab-cv-side-search');
+    const sortSel = panel.querySelector('#ab-cv-side-sort');
+    try { _abRosterSort = localStorage.getItem('ttsvc_ab_side_sort') || 'count'; } catch (_) {}
+    if (sortSel) sortSel.value = _abRosterSort;
+    let _t = null;
+    searchInp?.addEventListener('input', () => {
+      clearTimeout(_t);
+      _t = setTimeout(() => { _abRosterFilter = searchInp.value; renderRoster(); }, 120);
+    });
+    sortSel?.addEventListener('change', () => {
+      _abRosterSort = sortSel.value;
+      try { localStorage.setItem('ttsvc_ab_side_sort', _abRosterSort); } catch (_) {}
+      renderRoster();
+    });
+  })();
+
   // Quick "also known as" shortcut right in the sidebar, so adding an alias
   // (e.g. "Garthai" for "Sharraz Garthai", or "Ork" for a role-only speaker)
   // doesn't require leaving the casting screen for the full Character Library
@@ -1996,25 +2048,45 @@ STRIKTE FORMAT- UND TEXTREGELN:
       const alias = (mergeName || inp.value.trim());
       if (!alias) { _abCloseAliasPopup(); return; }
       const mergeTarget = otherByLower.get(alias.toLowerCase());
-      try {
-        const book = window.readerState?.title || '';
-        const rec = await clUpsert(book, { name, aliases: alias });
-        if (rec) { registerCharacterRecord(rec); if (_hlCache) _hlCache.ver = -1; }
-        if (mergeTarget) {
-          // The typed/picked name is an EXISTING roster entry, not just a new
-          // alias string — actually reassign its segments to this character
-          // so the two split roster entries become one, not just a linked
-          // library alias that leaves the live cast still showing both.
-          const n = _abMergeCharacters(mergeTarget, name);
+      _abCloseAliasPopup();
+      if (mergeTarget) {
+        // Merging rewrites every matching segment (fast) then has to rebuild
+        // the whole feed DOM — on a big book (thousands of rows, each running
+        // highlightText's regex pass) that redraw alone blocks the main
+        // thread long enough to trigger the browser's own "Page Unresponsive"
+        // dialog, not just look a bit slow. A spinner overlay by itself can't
+        // fix that — it would freeze right along with everything else, since
+        // it's all one synchronous JS turn. The redraw has to actually be
+        // chunked across animation frames so the browser can keep painting,
+        // which is also what makes a real (not fake) progress bar possible.
+        const busy = _abShowBusyOverlay(`Merging "${mergeTarget}" into ${name}…`, true);
+        await new Promise(r => requestAnimationFrame(r));
+        try {
+          const book = window.readerState?.title || '';
+          const rec = await clUpsert(book, { name, aliases: alias });
+          if (rec) { registerCharacterRecord(rec); if (_hlCache) _hlCache.ver = -1; }
+          const { changed: n, arr } = _abMergeCharacters(mergeTarget, name);
+          if (n) {
+            await _abRedrawSegmentsChunked(arr, (done, total) => busy.setProgress(done, total));
+            _abPersistManualEdit();
+          }
           toast(n ? `Merged "${mergeTarget}" into ${name} (${n} line${n !== 1 ? 's' : ''})` : `"${alias}" added as an alias for ${name}`, 'success');
-        } else {
+        } catch (err) {
+          toast('Could not merge: ' + (err.message || err), 'error');
+        } finally {
+          busy.remove();
+        }
+      } else {
+        try {
+          const book = window.readerState?.title || '';
+          const rec = await clUpsert(book, { name, aliases: alias });
+          if (rec) { registerCharacterRecord(rec); if (_hlCache) _hlCache.ver = -1; }
           renderRoster();
           toast(`"${alias}" added as an alias for ${name}`, 'success');
+        } catch (err) {
+          toast('Could not save alias: ' + (err.message || err), 'error');
         }
-      } catch (err) {
-        toast('Could not save alias: ' + (err.message || err), 'error');
       }
-      _abCloseAliasPopup();
     };
     el.querySelector('.ab-alias-save').addEventListener('click', () => doSave());
     el.querySelector('.ab-alias-cancel').addEventListener('click', () => _abCloseAliasPopup());
@@ -2037,9 +2109,13 @@ STRIKTE FORMAT- UND TEXTREGELN:
   // — used when the LLM split one character into two roster entries (e.g.
   // "Darag" / "Schmied" for the same person) and the user picks the other
   // entry from the alias popup instead of typing a plain-text alias.
+  // Only relabels segments (fast, plain array loop) — the caller is
+  // responsible for redrawing the feed afterward, since on a big book that
+  // part is the slow one and needs to run through the chunked path with
+  // visible progress instead of blocking the main thread outright.
   function _abMergeCharacters(fromName, intoName) {
     const active = _abActiveSegments();
-    if (!active.arr.length) return 0;
+    if (!active.arr.length) return { changed: 0, arr: active.arr };
     _abPushEditState(active.key, active.arr);
     let changed = 0;
     for (const s of active.arr) {
@@ -2048,12 +2124,7 @@ STRIKTE FORMAT- UND TEXTREGELN:
         changed++;
       }
     }
-    if (changed) {
-      _abRecountRoster(active.arr);
-      _abRedrawSegments(active.arr);
-      _abPersistManualEdit();
-    }
-    return changed;
+    return { changed, arr: active.arr };
   }
 
   (async () => {
@@ -2386,6 +2457,42 @@ STRIKTE FORMAT- UND TEXTREGELN:
       _abSelectChar(selectedChar);
     }
   };
+  // Same as _abRedrawSegments, but builds the feed in batches across several
+  // animation frames instead of one long synchronous loop — a full redraw on
+  // a big book (thousands of rows, each running highlightText's regex pass)
+  // blocks the main thread long enough to trigger the browser's own "Page
+  // Unresponsive" warning. Used by operations that redraw the WHOLE feed at
+  // once (character merge); the normal single-segment edits stay on the
+  // plain synchronous path since those are cheap regardless.
+  const _abRedrawSegmentsChunked = (segs, onProgress, batchSize = 150) => new Promise(resolve => {
+    const selectedChar = (!_abBar.hidden && _abBar.dataset.charName) ? _abBar.dataset.charName : '';
+    feed.innerHTML = '';
+    _abCurPage = null;
+    const list = segs || [];
+    let i = 0, lastPage = null;
+    const step = () => {
+      const end = Math.min(i + batchSize, list.length);
+      for (; i < end; i++) {
+        const s = list[i];
+        if (s.page != null && s.page !== lastPage) {
+          _abNewPage('Page ' + s.page, s.page);
+          lastPage = s.page;
+        }
+        _abPage().appendChild(_abRowFromSegment(s));
+      }
+      if (onProgress) onProgress(i, list.length);
+      if (i < list.length) {
+        requestAnimationFrame(step);
+      } else {
+        _abRecountRoster(list);
+        _abClearHL();
+        _abUpdatePageNav();
+        if (selectedChar) { _abBar.hidden = true; _abSelectChar(selectedChar); }
+        resolve();
+      }
+    };
+    requestAnimationFrame(step);
+  });
   const _abRestoreEditState = (snap) => {
     if (!snap) return;
     const restored = _abCloneSegments(snap.segments);
diff --git a/static/style.css b/static/style.css
index b589c60..5809e62 100644
--- a/static/style.css
+++ b/static/style.css
@@ -5424,6 +5424,17 @@ code { background: var(--panel); border-radius: 4px; padding: 1px 5px; font-fami
 .ab-cv-side-collapse { border: none; background: none; color: var(--subtext); cursor: pointer; padding: 2px; border-radius: 4px; line-height: 1; flex-shrink: 0; }
 .ab-cv-side-collapse:hover { background: var(--surface); color: var(--text); }
 .ab-cv-side-done { margin-top: 8px; padding-top: 8px; border-top: 1px solid var(--border); flex: 0 0 auto; }
+.ab-cv-side-tools { display: flex; gap: 4px; margin-bottom: 6px; flex: 0 0 auto; }
+.ab-cv-side-search {
+  flex: 1; min-width: 0; padding: 4px 7px; font-size: 11.5px; border: 1px solid var(--border);
+  border-radius: 5px; background: var(--surface); color: var(--text); outline: none;
+}
+.ab-cv-side-search:focus { border-color: var(--accent); }
+.ab-cv-side-sort {
+  padding: 4px 5px; font-size: 11px; border: 1px solid var(--border); border-radius: 5px;
+  background: var(--surface); color: var(--text); cursor: pointer; flex-shrink: 0;
+}
+.ab-cv-side.is-collapsed .ab-cv-side-tools { display: none; }
 .ab-cv-chars { display: flex; flex-direction: column; gap: 2px; min-height: 0; overflow-y: auto; padding-right: 2px; }
 .ab-cv-empty { font-size: 12px; color: var(--subtext); font-style: italic; }
 /* Collapsed sidebar: shrink to just the avatar dots, hide name/count/labels.