fix(clone): keep the preview and the wording on the parent folder

The "Will clone into" line named a folder the request would not use: the
preflight replaces the page's guessed case name with the server's (for a
URL such as .../repo?tab=readme the guess is repo-tab-readme and the server
says repo) and nothing refreshed the preview, so it stayed on the old name
while the field and the request moved on. It is now refreshed there too.

The Browse picker's title and the empty-field toast still said "Choose the
folder to clone into", the old exact-target meaning. Both now ask for the
parent folder, matching the field's label.

CLAUDE.md and the invariants paragraph split the two meanings: path on the
API is the exact folder, the Clone Repo tab's field is a parent and the page
sends <folder>/<case name>.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/web/public/session-ui.js

@@ -4291,7 +4291,7 @@ Object.assign(CodemanApp.prototype, {
   openCloneCasePathPicker() {
     const input = document.getElementById('cloneCasePath');
     PathPicker.open({
-      title: 'Choose the folder to clone into',
+      title: 'Choose the parent folder for the clone',
       initialPath: input.value.trim(),
       directoriesOnly: true,
       onSelect: (path) => {
@@ -4400,7 +4400,10 @@ Object.assign(CodemanApp.prototype, {
     // The server's suggestion wins over the local guess (it is the same function
     // the case name is validated against), but never over a name the user typed.
     const nameInput = document.getElementById('cloneCaseName');
-    if (nameInput && !this._cloneNameEdited && parse.suggestedName) nameInput.value = parse.suggestedName;
+    if (nameInput && !this._cloneNameEdited && parse.suggestedName) {
+      nameInput.value = parse.suggestedName;
+      this.updateCloneCasePathPreview();
+    }
 
     const where = parse.owner ? `${parse.provider} ${parse.owner}/${parse.repo}` : `${parse.provider} ${parse.repo}`;
     if (data.gitAvailable === false) {
@@ -4455,7 +4458,7 @@ Object.assign(CodemanApp.prototype, {
 
     const customFolder = !!document.getElementById('cloneCustomPathToggle')?.checked;
     if (customFolder && !(document.getElementById('cloneCasePath')?.value || '').trim()) {
-      this.showToast('Choose the folder to clone into', 'error');
+      this.showToast('Choose the parent folder for the clone', 'error');
       return;
     }