fix: release local preview object URLs

CHANGELOG.md

@@ -55,6 +55,8 @@ Follows [Keep a Changelog](https://keepachangelog.com/en/1.0.0/) · versioned wi
   original temporary result; reusing a key for different request data is rejected.
 - **Casting Idempotency.** Character-to-voice matching now applies the same bounded, expiring idempotency contract,
   preventing repeated clicks from issuing duplicate LLM casting requests.
+- **Preview Blob Lifecycle.** Character-library and Rehearser local voice previews now revoke replaced or completed
+  object URLs, reducing retained browser memory during repeated auditioning.
 - **Security Regression Coverage.** Added a Python test gate for character metadata validation, private-download URL
   rejection and oversized JSON request rejection.
 - **Navigation Reliability.** Rehearser phase requests now survive the feature-module initialization boundary.

TODO.md

@@ -111,7 +111,8 @@ the first block before investing in architecture or polish.
 - [ ] Update only affected table rows instead of rebuilding entire tables.
 - [ ] Add an LRU cache for audio and images and remove old entries automatically. Persisted line-audio is now bounded;
   image-cache eviction remains.
-- [x] Revoke discarded object URLs with `URL.revokeObjectURL(objectUrl)`; completed synthesized voice previews now release their Blob URLs when playback ends.
+- [x] Revoke discarded object URLs with `URL.revokeObjectURL(objectUrl)`; completed synthesized voice previews and
+  character/Rehearser local auditions now release their Blob URLs when playback ends or is replaced.
 - [x] Add low-memory mode using `navigator.deviceMemory` where available; shared worker pools cap at two tasks on devices reporting approximately 4 GB RAM or less.
 - [ ] Disable image preloading and reduce table/cache sizes on devices with approximately 4 GB RAM.
 

static/js/library-characters.js

@@ -2705,6 +2705,7 @@ function _confirmVoiceReuse(rec, reuse) {
       + '</div>';
     document.body.appendChild(ov);
     let audioEl = null;
+    let audioObjectUrl = null;
     ov.querySelector('#cvr-play').addEventListener('click', async function (e) {
       const btn = e.currentTarget;
       const icon = btn.querySelector('.mdi');
@@ -2720,8 +2721,16 @@ function _confirmVoiceReuse(rec, reuse) {
         const rv = (window._voices || []).find(x => x.id === reuse.voiceId);
         const rBackend = (rv && !rv.has_ref) ? 'voice_design' : 'voice_clone';
         const blob = await fetchTtsPreviewBlob(reuse.voiceId, text, 'wav', '', rBackend);
-        if (!audioEl) { audioEl = new Audio(); audioEl.addEventListener('ended', function () { icon.className = 'mdi mdi-play'; }); }
-        audioEl.src = URL.createObjectURL(blob);
+        if (!audioEl) {
+          audioEl = new Audio();
+          audioEl.addEventListener('ended', function () {
+            icon.className = 'mdi mdi-play';
+            if (audioObjectUrl) { URL.revokeObjectURL(audioObjectUrl); audioObjectUrl = null; }
+          });
+        }
+        if (audioObjectUrl) URL.revokeObjectURL(audioObjectUrl);
+        audioObjectUrl = URL.createObjectURL(blob);
+        audioEl.src = audioObjectUrl;
         await audioEl.play();
         icon.className = 'mdi mdi-pause';
       } catch (err) { toast('Could not play sample: ' + (err.message || err), 'error'); icon.className = 'mdi mdi-play'; }
@@ -2729,6 +2738,7 @@ function _confirmVoiceReuse(rec, reuse) {
     });
     const cleanup = function (result) {
       if (audioEl) audioEl.pause();
+      if (audioObjectUrl) { URL.revokeObjectURL(audioObjectUrl); audioObjectUrl = null; }
       ov.remove();
       resolve(result);
     };

static/js/rehearser.js

@@ -1064,9 +1064,10 @@ function castAvatarHtml(sp) {
 }
 
 // ── Online voice picker: audition a sample, browse alternatives, agree/switch ──
-let _rehAudEl = null, _rehAudBtn = null;
+let _rehAudEl = null, _rehAudBtn = null, _rehAudObjectUrl = null;
 function _rehStopAudition() {
   if (_rehAudEl) { try { _rehAudEl.pause(); } catch (_) {} }
+  if (_rehAudObjectUrl) { URL.revokeObjectURL(_rehAudObjectUrl); _rehAudObjectUrl = null; }
   if (_rehAudBtn) { _rehAudBtn.classList.remove('playing'); const i = _rehAudBtn.querySelector('.mdi'); if (i) i.className = 'mdi mdi-play'; }
   _rehAudBtn = null;
 }
@@ -1151,7 +1152,8 @@ async function _rehPreviewLocal(voiceId, btn) {
   try {
     const blob = await fetchTtsPreviewBlob(voiceId, _REH_PREVIEW_TEXT, 'wav', '', backend);
     if (!_rehAudEl) { _rehAudEl = new Audio(); _rehAudEl.addEventListener('ended', _rehStopAudition); }
-    _rehAudEl.src = URL.createObjectURL(blob);
+    _rehAudObjectUrl = URL.createObjectURL(blob);
+    _rehAudEl.src = _rehAudObjectUrl;
     await _rehAudEl.play();
     btn.classList.remove('loading'); _rehAudBtn = btn; btn.classList.add('playing');
     if (icon) icon.className = 'mdi mdi-stop';