fix(window-tabs-panes): render group header for every multi-pane vertical tab

app/src/workspace/view/vertical_tabs.rs

@@ -1953,11 +1953,16 @@ fn render_tab_group_internal(
             rows.finish()
         };
 
+        let show_header = should_show_tab_group_header(
+            has_custom_title,
+            is_being_renamed,
+            visible_pane_ids.len(),
+        );
         let group_content = if uses_outer_group_container {
             let mut group = Flex::column()
                 .with_main_axis_size(MainAxisSize::Min)
                 .with_cross_axis_alignment(CrossAxisAlignment::Stretch);
-            if has_custom_title || is_being_renamed {
+            if show_header {
                 group.add_child(render_group_header(
                     GroupHeaderProps {
                         tab_index,
@@ -1970,7 +1975,6 @@ fn render_tab_group_internal(
                 ));
             }
 
-            let show_header = has_custom_title || is_being_renamed;
             let mut body_padding = Padding::uniform(0.)
                 .with_left(GROUP_HORIZONTAL_PADDING)
                 .with_right(GROUP_HORIZONTAL_PADDING)
@@ -2950,6 +2954,30 @@ fn uses_outer_group_container(display_granularity: VerticalTabsDisplayGranularit
     matches!(display_granularity, VerticalTabsDisplayGranularity::Panes)
 }
 
+/// Decides whether to render the tab-group header above a multi-row group in
+/// `Panes` granularity.
+///
+/// The header is shown when:
+///   * the tab has a user-set custom title (rename flow), or
+///   * the tab is currently being renamed (inline editor), or
+///   * the tab contains more than one visible pane.
+///
+/// The third condition is what fixes issue #9098: previously the header was
+/// only shown when a custom title existed, so multi-pane tabs with auto-
+/// generated names (the AI/CLI session naming flow) rendered without any
+/// tab-level identifier — only their first row's title was visible, which
+/// looked identical for every tab and made the bar appear "nameless".
+/// Single-pane groups in `Panes` mode still omit the header because the
+/// single row already shows the pane title (avoids duplicating the same
+/// text immediately above itself).
+fn should_show_tab_group_header(
+    has_custom_title: bool,
+    is_being_renamed: bool,
+    visible_pane_count: usize,
+) -> bool {
+    has_custom_title || is_being_renamed || visible_pane_count > 1
+}
+
 fn search_fragments_contain_query(fragments: &[String], query_lower: &str) -> bool {
     fragments
         .iter()

app/src/workspace/view/vertical_tabs_tests.rs

@@ -17,7 +17,8 @@ use super::{
     non_terminal_search_text_fragments, pane_ids_for_display_granularity,
     pane_search_text_fragments, preferred_agent_tab_titles, search_fragments_contain_query,
     select_summary_pane_kind_icons, should_keep_detail_sidecar_visible_for_mouse_position,
-    summary_overflow_count, summary_search_text_fragments, terminal_kind_badge_label,
+    should_show_tab_group_header, summary_overflow_count, summary_search_text_fragments,
+    terminal_kind_badge_label,
     terminal_primary_line_data, terminal_pull_request_badge_label, terminal_search_text_fragments,
     terminal_title_fallback_font, uses_outer_group_container, visible_pane_ids_for_detail_target,
     vtab_diff_stats_text, AgentTabTextPreference, SummaryPaneKind, SummaryPaneKindIcons,
@@ -589,6 +590,62 @@ fn tabs_granularity_does_not_use_outer_group_container() {
     ));
 }
 
+// Regression coverage for #9098 ("Tab names not rendered in tab bar, only
+// first tab shows name"). The header gate previously read `has_custom_title
+// || is_being_renamed`, which collapsed to `false` for every tab without a
+// user-set rename — leaving multi-pane tabs with auto-generated names
+// looking like they had no tab label at all. The new gate keeps the existing
+// triggers and adds "any multi-pane tab", so every multi-pane group has a
+// stable tab-level identifier in `Panes` granularity.
+#[test]
+fn tab_group_header_shows_for_custom_title() {
+    assert!(should_show_tab_group_header(true, false, 1));
+    assert!(should_show_tab_group_header(true, false, 3));
+}
+
+#[test]
+fn tab_group_header_shows_while_renaming() {
+    // The inline rename editor must always be reachable, even on
+    // single-pane tabs with no prior custom title.
+    assert!(should_show_tab_group_header(false, true, 1));
+}
+
+#[test]
+fn tab_group_header_shows_for_multi_pane_tabs_without_custom_title() {
+    // The #9098 case: an auto-named multi-pane tab. Each row only shows the
+    // per-pane title (e.g. `travelplan` + `main`), so without a group header
+    // there is no way to tell two such tabs apart in the sidebar.
+    assert!(should_show_tab_group_header(false, false, 2));
+    assert!(should_show_tab_group_header(false, false, 5));
+}
+
+#[test]
+fn tab_group_header_hidden_for_single_pane_without_custom_title() {
+    // Single-pane groups already surface the pane title in their only row.
+    // Rendering the same string again as a header would duplicate it
+    // immediately above itself, so the gate stays closed in this shape.
+    assert!(!should_show_tab_group_header(false, false, 1));
+    // Defensive: `0` should not crash or accidentally render a header for
+    // an empty group (this shape shouldn't reach the renderer in practice,
+    // but the helper is total and stays closed).
+    assert!(!should_show_tab_group_header(false, false, 0));
+}
+
+#[test]
+fn tab_group_header_distinguishes_two_auto_named_multi_pane_tabs() {
+    // Models the screenshot in #9098: tab 1 has a custom title
+    // ("Humanfigure"), tabs 2 and 3 are auto-named multi-pane groups
+    // ("travelplan + main", "deponti + release/development"). Before the
+    // fix only tab 1 showed a header; after the fix every multi-pane tab
+    // gets one so the user can tell them apart at a glance.
+    let renders_header: Vec<bool> = vec![
+        should_show_tab_group_header(true, false, 2),  // tab 1
+        should_show_tab_group_header(false, false, 2), // tab 2
+        should_show_tab_group_header(false, false, 2), // tab 3
+    ];
+    assert_eq!(renders_header, vec![true, true, true]);
+}
+
 #[test]
 fn terminal_primary_line_prefers_cli_agent_display_title() {
     let line = terminal_primary_line_data(