fix(modals): keep restored settings and theme windows open (#6924)

* fix(modals): keep restored settings and theme windows open

* fix(theme): cancel closing on a rapid toggle reopen

* test: isolate photo routing from external MCP registry state

* fix(cache): preserve the upstream editor worker key format

static/js/modalVisibility.js

@@ -0,0 +1,42 @@
+// Own both completion paths of an animated close so neither can outlive it.
+const _pendingCloses = new WeakMap();
+
+function cancelClose(modal) {
+  const pending = _pendingCloses.get(modal);
+  if (!pending) return;
+  clearTimeout(pending.timer);
+  pending.content.removeEventListener('animationend', pending.onEnd);
+  pending.content.classList.remove('modal-closing');
+  _pendingCloses.delete(modal);
+}
+
+export function showModal(modal) {
+  if (!modal) return;
+  cancelClose(modal);
+  modal.classList.remove('hidden');
+}
+
+export function hideModal(modal) {
+  if (!modal) return;
+  cancelClose(modal);
+  const content = modal.querySelector('.modal-content, .settings-modal-content');
+  // A minimized window has no exit animation. Registering a listener here
+  // would let its next entrance animation close the newly opened window.
+  if (!content || modal.classList.contains('hidden')) {
+    modal.classList.add('hidden');
+    return;
+  }
+  const pending = { content, timer: null, onEnd: null };
+  const finish = () => {
+    if (_pendingCloses.get(modal) !== pending) return;
+    cancelClose(modal);
+    modal.classList.add('hidden');
+  };
+  pending.onEnd = event => {
+    if (event.target === content) finish();
+  };
+  _pendingCloses.set(modal, pending);
+  content.classList.add('modal-closing');
+  content.addEventListener('animationend', pending.onEnd);
+  pending.timer = setTimeout(finish, 250);
+}