Generate descriptive TUI thread titles (#40492)

## What changed

- Give unnamed TUI threads an immediate provisional title from the first user message, then replace it asynchronously with a normalized generated title.
- Preserve manual renames by applying a generated title only while the provisional title is still current, and keep automatic rename notifications out of the transcript.
- Run title generation in a bounded ephemeral structured request that preserves custom permission profiles, otherwise uses read-only access, and disables tools and MCP servers.

## Testing

- Cover prompt and response bounds, Unicode-safe truncation, title normalization, manual-rename races, silent automatic updates, permission preservation, and structured-response failures.

GitOrigin-RevId: 7ed73522f4f6c65a005f65f3a903974d8419e312

codex-rs/tui/src/chatwidget/session_flow.rs

@@ -25,6 +25,7 @@ impl ChatWidget {
         self.bottom_pane
             .set_queue_submissions(/*queue_submissions*/ false);
         if previous_thread_id != self.thread_id {
+            self.pending_automatic_thread_names.clear();
             self.review.recent_auto_review_denials = RecentAutoReviewDenials::default();
             self.clear_thread_usage_state();
         }
@@ -245,16 +246,38 @@ impl ChatWidget {
         )));
     }
 
+    /// Apply a persisted automatic name immediately and suppress its confirmation.
+    pub(crate) fn expect_automatic_thread_name(&mut self, name: String) {
+        self.thread_name = Some(name.clone());
+        self.pending_automatic_thread_names.insert(name);
+    }
+
+    /// Make a confirmed manual rename visible before its queued server notification arrives.
+    pub(crate) fn expect_manual_thread_name(&mut self, thread_id: ThreadId, name: String) {
+        if self.thread_id == Some(thread_id) {
+            self.thread_name = Some(name);
+            self.refresh_status_surfaces();
+            self.request_redraw();
+        }
+    }
+
     pub(super) fn on_thread_name_updated(
         &mut self,
         thread_id: ThreadId,
         thread_name: Option<String>,
     ) {
         if self.thread_id == Some(thread_id) {
-            if let Some(name) = thread_name.as_deref() {
+            let automatic = thread_name
+                .as_ref()
+                .is_some_and(|name| self.pending_automatic_thread_names.remove(name));
+
+            if let Some(name) = thread_name.as_deref()
+                && !automatic
+            {
                 let cell = Self::rename_confirmation_cell(name, self.thread_id);
                 self.add_boxed_history(Box::new(cell));
             }
+
             self.thread_name = thread_name;
             self.refresh_status_surfaces();
             self.request_redraw();