Support skills shortDescription. (#8278)

Allow SKILL.md to specify a more human-readable short description as
skill metadata.

codex-rs/tui2/src/bottom_pane/skill_popup.rs

@@ -86,7 +86,11 @@ impl SkillPopup {
                     .and_then(|n| n.to_str())
                     .unwrap_or(&skill.name);
                 let name = format!("{} ({slug})", skill.name);
-                let description = skill.description.clone();
+                let description = skill
+                    .short_description
+                    .as_ref()
+                    .unwrap_or(&skill.description)
+                    .clone();
                 GenericDisplayRow {
                     name,
                     match_indices: indices,

codex-rs/tui2/src/chatwidget.rs

@@ -3539,6 +3539,7 @@ fn skills_for_cwd(cwd: &Path, skills_entries: &[SkillsListEntry]) -> Vec<SkillMe
                 .map(|skill| SkillMetadata {
                     name: skill.name.clone(),
                     description: skill.description.clone(),
+                    short_description: skill.short_description.clone(),
                     path: skill.path.clone(),
                     scope: skill.scope,
                 })