gate-fix #5467 r2: force render when recovering from skeleton/error-banner DOM

Codex re-gate found 2 more false-skips (DOM state OUTSIDE the signature path):
- CORE: profile-switch skeleton stays visible if the new payload signature
  matches the last one (empty/same-shaped profile) — skip fires over the skeleton.
- SILENT: stale 'Could not load conversations' banner persists when a transient
  fetch failure heals with identical rows.
Fix: capture _hadSessionListSkeleton + _hadSessionListLoadError BEFORE clearing
them, and disallow the identical-signature skip when either was set. + regression
test. (messages.js:1462 finding is a base-comparison artifact for #5472/#5479/#5484,
not in #5467's diff.)

static/sessions.js

@@ -4436,6 +4436,11 @@ function _applySessionListPayload(sessData, projData){
   _syncSessionAttentionSoundState(_allSessions);
   _pruneLineageReportCacheToVisibleSessions(_allSessions);
   _allProjects = projData.projects||[];
+  // Capture the recovering-from-error state BEFORE clearing it: the error banner
+  // DOM was rendered outside the signature path, so if this payload heals with
+  // rows identical to the last render, the identical-signature skip below would
+  // leave the stale "Could not load conversations" banner on screen. (Codex #5467)
+  const _hadSessionListLoadError = !!_sessionListLoadError;
   _sessionListLoadError = null;
   _sessionListHasLoadedOnce = true;
   _markPollingCompletionUnreadTransitions(_allSessions);
@@ -4457,6 +4462,7 @@ function _applySessionListPayload(sessData, projData){
   // holds the CURRENT profile's rows. Clear the skeleton flag right before painting so this
   // authoritative render replaces the profile-switch skeleton — while unrelated renders that
   // fire before this point stay blocked by the guard in renderSessionListFromCache().
+  const _hadSessionListSkeleton = _sessionListSkeletonActive;
   _sessionListSkeletonActive = false;
   // No-op fast path: if this payload renders identically to what is already on
   // screen (the common case for idle polls) and no entrance animation is
@@ -4465,9 +4471,13 @@ function _applySessionListPayload(sessData, projData){
   // renderSessionListFromCache directly and are unaffected. Guarded by the same
   // conditions renderSessionListFromCache bails on, so a bailed render never
   // caches a signature that would suppress the next real repaint. (#5455 WS2.4)
+  // NEVER skip when recovering from a skeleton or error-banner DOM state: those
+  // are rendered outside the signature path, so an identical-signature match
+  // would leave the skeleton/error on screen instead of the real list. (Codex #5467)
   const _canRenderNow = !_renamingSid && !_sessionActionMenu;
+  const _mustForceRender = _hadSessionListSkeleton || _hadSessionListLoadError;
   const _renderSig = _sessionListRenderSignature();
-  if(_canRenderNow && !_sessionListRefreshAnimationPending && _renderSig && _renderSig===_lastSessionListRenderSig){
+  if(_canRenderNow && !_mustForceRender && !_sessionListRefreshAnimationPending && _renderSig && _renderSig===_lastSessionListRenderSig){
     // Preserve the per-refresh INFLIGHT cleanup that renderSessionListFromCache
     // would otherwise perform, then skip only the DOM rebuild.
     if(typeof _purgeStaleInflightEntries==='function') _purgeStaleInflightEntries();

tests/test_webui_external_refresh_frontend.py

@@ -176,6 +176,25 @@ def test_session_list_render_signature_changes_on_pending_running_and_attention(
     assert "JSON.stringify([" in block
 
 
+def test_session_list_render_signature_does_not_skip_recovering_from_skeleton_or_error():
+    """The render-skip must never fire when recovering from a skeleton or the
+    'Could not load conversations' banner — both are rendered OUTSIDE the
+    signature path, so an identical-signature match (empty/same-shaped profile,
+    or a transient fetch failure healing with identical rows) would leave the
+    skeleton/error DOM on screen instead of the real list. (Codex #5467 re-gate)
+    """
+    start = SESSIONS_JS.find("function _applySessionListPayload(")
+    assert start != -1
+    body = SESSIONS_JS[start:start + 6000]
+    assert "const _hadSessionListSkeleton = _sessionListSkeletonActive;" in body
+    assert "const _hadSessionListLoadError = !!_sessionListLoadError;" in body
+    assert "const _mustForceRender = _hadSessionListSkeleton || _hadSessionListLoadError;" in body
+    assert "!_mustForceRender" in body, "the force flag must gate the identical-signature skip"
+    # captured BEFORE the respective clears
+    assert body.index("const _hadSessionListSkeleton") < body.index("_sessionListSkeletonActive = false;")
+    assert body.index("const _hadSessionListLoadError") < body.index("_sessionListLoadError = null;")
+
+
 def test_pwa_pull_to_refresh_refreshes_session_list_not_page_when_available():
     assert "window.refreshSessionList('pull', {force:true, refreshActive:true})" in UI_JS
     assert "Promise.resolve(window.refreshSessionList('pull', {force:true, refreshActive:true})).catch(()=>{}).finally(_ptrReset)" in UI_JS