feat(maestro): show spawn-similar and kill affordances on the highlighted card

Line-1 actions anchor to the card's top-right corner on the highlighted
row only, reserving their width so the name truncates with an ellipsis
before it can ever reach them.

crates/maestro-tui/src/sidebar.rs

@@ -21,6 +21,8 @@ use uuid::Uuid;
 const META_LINE_AFTER_SECS: i64 = 30;
 const INDENT: &str = "  ";
 const META_INDENT: &str = "    ";
+/// Spawn-similar and kill, shown on the highlighted card's top-right corner.
+const ACTIONS: &str = "⧉ ✕";
 
 /// Every card sits on this background so cards read as cards against the
 /// panel; the highlighted card swaps it for the focus background instead
@@ -71,11 +73,7 @@ impl Sidebar {
         for s in &self.sessions {
             let highlighted = self.highlight == Some(s.id);
             let base = card_base(highlighted);
-            lines.push(Line::from(pad_to_width(
-                self.name_row(s, width),
-                width,
-                base,
-            )));
+            lines.push(Line::from(self.name_row(s, width)));
             if let Some(meta) = self.meta_row(s, width) {
                 lines.push(Line::from(pad_to_width(meta, width, base)));
             }
@@ -91,15 +89,41 @@ impl Sidebar {
         };
         let highlighted = self.highlight == Some(s.id);
         let base = card_base(highlighted);
-        let row = vec![
-            Span::raw(INDENT),
-            Span::raw(format!("{glyph} ")),
-            Span::raw(name_for(s)),
+        // Line-1 actions are keyboard affordances shown on the highlighted
+        // row only; they reserve their width so the name truncates with `…`
+        // before it can ever reach them (docs/SIDEBAR.md).
+        let actions_width = if highlighted {
+            ACTIONS.chars().count()
+        } else {
+            0
+        };
+        let usable = width.saturating_sub(actions_width);
+        let prefix = INDENT.chars().count() + 2;
+        // Keep one column of separation between a truncated name and the
+        // actions so the ellipsis never touches them.
+        let sep = if highlighted { 1 } else { 0 };
+        let name_budget = usable.saturating_sub(prefix + sep);
+
+        let mut spans: Vec<Span<'static>> = vec![
+            Span::styled(INDENT, base),
+            Span::styled(format!("{glyph} "), base),
         ];
-        fit_to_width(row, width)
-            .into_iter()
-            .map(|sp| Span::styled(sp.content, base.patch(sp.style)))
-            .collect()
+        spans.extend(
+            fit_to_width(vec![Span::raw(name_for(s))], name_budget)
+                .into_iter()
+                .map(|sp| Span::styled(sp.content, base.patch(sp.style))),
+        );
+        let used: usize = spans.iter().map(|sp| sp.width()).sum();
+        if let Some(fill) = usable.checked_sub(used).filter(|&n| n > 0) {
+            spans.push(Span::styled(
+                " ".repeat(fill),
+                Style::default().bg(base.bg.unwrap_or(Color::Reset)),
+            ));
+        }
+        if highlighted {
+            spans.push(Span::styled(ACTIONS, base));
+        }
+        spans
     }
 
     /// The adaptive second line: `<dot> <duration> [<blocked work> | exited]`.
@@ -596,4 +620,61 @@ mod tests {
             );
         }
     }
+
+    /// Line 1's actions live on the highlighted row's top-right corner.
+    #[test]
+    fn highlighted_row_anchors_the_actions_top_right() {
+        let sb = Sidebar {
+            sessions: vec![session_named(1, "claude")],
+            highlight: Some(Uuid::from_u128(1)),
+            attached: Default::default(),
+        };
+        let all = rows(&draw(&sb, 28, 8));
+        let line = content(row_containing(&all, "claude"));
+        assert!(
+            line.ends_with("⧉ ✕"),
+            "actions must sit at the right edge: {line:?}"
+        );
+    }
+
+    #[test]
+    fn unhighlighted_rows_show_no_actions() {
+        let one = session_named(1, "claude");
+        let two = session_named(2, "bash");
+        let sb = Sidebar {
+            sessions: vec![one, two],
+            highlight: Some(Uuid::from_u128(1)),
+            attached: Default::default(),
+        };
+        let all = rows(&draw(&sb, 28, 8));
+        let line = row_containing(&all, "bash");
+        assert!(
+            !line.contains('⧉') && !line.contains('✕'),
+            "actions are highlight-only: {line:?}"
+        );
+    }
+
+    /// The name truncates with `…` before it can ever reach the reserved
+    /// action width (docs/SIDEBAR.md — overlap is a defect).
+    #[test]
+    fn name_truncates_before_reaching_the_actions() {
+        let mut s = session_named(1, "claude");
+        if let Some(serde_json::Value::String(name)) = s.metadata.get_mut("name") {
+            *name = "an-unreasonably-long-session-name".into();
+        }
+        let sb = Sidebar {
+            sessions: vec![s],
+            highlight: Some(Uuid::from_u128(1)),
+            attached: Default::default(),
+        };
+        let all = rows(&draw(&sb, 28, 8));
+        let line = row_containing(&all, "an-unreasonably");
+        let name_end = line.find('…').expect("name must truncate with …");
+        let actions_start = line.find('⧉').expect("actions must still render");
+        assert!(name_end < actions_start, "name overlaps actions: {line:?}");
+        assert!(
+            line.split_at(actions_start).0.ends_with(' '),
+            "no gap before the actions: {line:?}"
+        );
+    }
 }