feat: Add more /review options (#3961)

Adds the following options:

1. Review current changes
2. Review a specific commit
3. Review against a base branch (PR style)
4. Custom instructions

<img width="487" height="330" alt="Screenshot 2025-09-20 at 2 11 36 PM"
src="https://github.com/user-attachments/assets/edb0aaa5-5747-47fa-881f-cc4c4f7fe8bc"
/>

---

\+ Adds the following UI helpers:

1. Makes list selection searchable
2. Adds navigation to the bottom pane, so you could add a stack of
popups
3. Basic custom prompt view

codex-rs/tui/src/bottom_pane/selection_popup_common.rs

@@ -13,6 +13,7 @@ use ratatui::widgets::BorderType;
 use ratatui::widgets::Borders;
 use ratatui::widgets::Paragraph;
 use ratatui::widgets::Widget;
+use unicode_width::UnicodeWidthChar;
 
 use super::scroll_state::ScrollState;
 use crate::ui_consts::LIVE_PREFIX_COLS;
@@ -55,10 +56,24 @@ fn compute_desc_col(
 /// at `desc_col`. Applies fuzzy-match bolding when indices are present and
 /// dims the description.
 fn build_full_line(row: &GenericDisplayRow, desc_col: usize) -> Line<'static> {
+    // Enforce single-line name: allow at most desc_col - 2 cells for name,
+    // reserving two spaces before the description column.
+    let name_limit = desc_col.saturating_sub(2);
+
     let mut name_spans: Vec<Span> = Vec::with_capacity(row.name.len());
+    let mut used_width = 0usize;
+    let mut truncated = false;
+
     if let Some(idxs) = row.match_indices.as_ref() {
         let mut idx_iter = idxs.iter().peekable();
         for (char_idx, ch) in row.name.chars().enumerate() {
+            let ch_w = UnicodeWidthChar::width(ch).unwrap_or(0);
+            if used_width + ch_w > name_limit {
+                truncated = true;
+                break;
+            }
+            used_width += ch_w;
+
             if idx_iter.peek().is_some_and(|next| **next == char_idx) {
                 idx_iter.next();
                 name_spans.push(ch.to_string().bold());
@@ -67,7 +82,21 @@ fn build_full_line(row: &GenericDisplayRow, desc_col: usize) -> Line<'static> {
             }
         }
     } else {
-        name_spans.push(row.name.clone().into());
+        for ch in row.name.chars() {
+            let ch_w = UnicodeWidthChar::width(ch).unwrap_or(0);
+            if used_width + ch_w > name_limit {
+                truncated = true;
+                break;
+            }
+            used_width += ch_w;
+            name_spans.push(ch.to_string().into());
+        }
+    }
+
+    if truncated {
+        // If there is at least one cell available, add an ellipsis.
+        // When name_limit is 0, we still show an ellipsis to indicate truncation.
+        name_spans.push("…".into());
     }
 
     let this_name_width = Line::from(name_spans.clone()).width();