fix(ui): label whitespace leader keys as <space>/<tab> in help popup

docs/CONFIG.md

@@ -75,7 +75,7 @@ legend = true
 | `show_file_list`           | `true`       | Whether the file list panel is visible on startup. Toggle with `<leader>e`.                                                                                |
 | `show_commits`             | `true`       | Whether the inline commit selector pane is visible on startup for multi-commit reviews. Toggle with `<leader>s` or `:set commits!`.                        |
 | `mouse`                    | `true`       | Wheel scrolling, clicks, and drag-to-select.                                                                                                               |
-| `leader`                   | `;`          | Single-character prefix for panel focus, sidebar toggles, and review-comment shortcuts. Invalid multi-character values are ignored with a startup warning. |
+| `leader`                   | `;`          | Single-character prefix for panel focus, sidebar toggles, and review-comment shortcuts. Whitespace leaders such as `leader = " "` are shown as `<space>` / `<tab>` in the in-app help. Invalid multi-character values are ignored with a startup warning. |
 | `comment_vim`              | `false`      | Vim modal editing in the comment box; toggle at runtime with `:vim`. When off, default emacs/readline bindings.                                            |
 | `comment_tab_width`        | `4`          | Spaces inserted by Tab while typing in the vim comment box (Insert mode).                                                                                  |
 | `wrap`                     | `false`      | Line wrap in the diff view. Toggle with `:set wrap!`.                                                                                                      |

docs/KEYBINDINGS.md

@@ -3,6 +3,7 @@
 Full reference. Press `?` inside tuicr for an in-app version of this list.
 
 `<leader>` defaults to `;`. Override it with `leader = ","` in `~/.config/tuicr/config.toml`.
+Whitespace leaders such as `leader = " "` show up as `<space>` (or `<tab>`) in the in-app help.
 
 ## Navigation
 

src/ui/help_popup.rs

@@ -8,8 +8,10 @@ use ratatui::{
 
 use crate::app::App;
 use crate::ui::styles;
+use crate::ui::text_utils::{key_label, shortcut_column};
 
 pub fn render_help(frame: &mut Frame, app: &mut App) {
+    let leader = key_label(app.leader_key);
     let theme = &app.theme;
     // Center over the diff pane (matches the submit-modal anchoring) so the
     // file list doesn't tug the popup's visual centre off to one side. Fall
@@ -135,35 +137,35 @@ pub fn render_help(frame: &mut Frame, app: &mut App) {
         ]),
         Line::from(vec![
             Span::styled(
-                format!("  {}h/{}l     ", app.leader_key, app.leader_key),
+                shortcut_column(&format!("{leader}h/{leader}l")),
                 Style::default().add_modifier(Modifier::BOLD),
             ),
             Span::raw("Focus file list/diff"),
         ]),
         Line::from(vec![
             Span::styled(
-                format!("  {}k/{}j     ", app.leader_key, app.leader_key),
+                shortcut_column(&format!("{leader}k/{leader}j")),
                 Style::default().add_modifier(Modifier::BOLD),
             ),
             Span::raw("Move focus up/down between panes"),
         ]),
         Line::from(vec![
             Span::styled(
-                format!("  {}e        ", app.leader_key),
+                shortcut_column(&format!("{leader}e")),
                 Style::default().add_modifier(Modifier::BOLD),
             ),
             Span::raw("Toggle file list visibility"),
         ]),
         Line::from(vec![
             Span::styled(
-                format!("  {}s        ", app.leader_key),
+                shortcut_column(&format!("{leader}s")),
                 Style::default().add_modifier(Modifier::BOLD),
             ),
             Span::raw("Toggle commit selector visibility (also `:set commits!`)"),
         ]),
         Line::from(vec![
             Span::styled(
-                format!("  {}f        ", app.leader_key),
+                shortcut_column(&format!("{leader}f")),
                 Style::default().add_modifier(Modifier::BOLD),
             ),
             Span::raw("Toggle single-file view (also `:focus` / `:f`)"),
@@ -188,7 +190,7 @@ pub fn render_help(frame: &mut Frame, app: &mut App) {
         ]),
         Line::from(""),
         Line::from(Span::styled(
-            format!("Single-file view (`:focus`, `:f`, {}f)", app.leader_key),
+            format!("Single-file view (`:focus`, `:f`, {leader}f)"),
             Style::default().add_modifier(Modifier::BOLD | Modifier::UNDERLINED),
         )),
         Line::from(""),
@@ -411,7 +413,7 @@ pub fn render_help(frame: &mut Frame, app: &mut App) {
         ]),
         Line::from(vec![
             Span::styled(
-                format!("  {}c        ", app.leader_key),
+                shortcut_column(&format!("{leader}c")),
                 Style::default().add_modifier(Modifier::BOLD),
             ),
             Span::raw("Add review comment"),
@@ -634,10 +636,7 @@ pub fn render_help(frame: &mut Frame, app: &mut App) {
                 "  :focus    ",
                 Style::default().add_modifier(Modifier::BOLD),
             ),
-            Span::raw(format!(
-                "Toggle single-file view (alias `:f`, {}f)",
-                app.leader_key
-            )),
+            Span::raw(format!("Toggle single-file view (alias `:f`, {leader}f)")),
         ]),
         Line::from(vec![
             Span::styled(

src/ui/text_utils.rs

@@ -26,6 +26,29 @@ pub(super) fn truncate_or_pad(s: &str, width: usize) -> String {
     }
 }
 
+/// Display label for a key that has no visible glyph, so shortcuts stay
+/// readable when the leader is configured as whitespace.
+pub(super) fn key_label(key: char) -> String {
+    match key {
+        ' ' => "<space>".to_string(),
+        '\t' => "<tab>".to_string(),
+        other => other.to_string(),
+    }
+}
+
+const KEY_COLUMN_WIDTH: usize = 10;
+
+/// Help popup key gutter: two-space indent plus a padded key column, keeping
+/// at least one space before the description when a label overflows it.
+pub(super) fn shortcut_column(keys: &str) -> String {
+    let width = keys.width();
+    if width >= KEY_COLUMN_WIDTH {
+        format!("  {keys} ")
+    } else {
+        format!("  {keys}{}", " ".repeat(KEY_COLUMN_WIDTH - width))
+    }
+}
+
 /// Truncate or pad highlighted spans to a specific display width
 /// Uses unicode width to properly handle wide characters (CJK, emoji, etc.)
 /// Returns a vector of spans that fits exactly within the width
@@ -298,6 +321,57 @@ mod tests {
         assert!(result.is_char_boundary(result.len()));
     }
 
+    #[test]
+    fn should_render_printable_key_as_itself() {
+        // given
+        let key = ';';
+        // when
+        let label = key_label(key);
+        // then
+        assert_eq!(label, ";");
+    }
+
+    #[test]
+    fn should_label_space_key_readably() {
+        // given - `leader = " "` in config.toml
+        let key = ' ';
+        // when
+        let label = key_label(key);
+        // then
+        assert_eq!(label, "<space>");
+    }
+
+    #[test]
+    fn should_label_tab_key_readably() {
+        // given
+        let key = '\t';
+        // when
+        let label = key_label(key);
+        // then
+        assert_eq!(label, "<tab>");
+    }
+
+    #[test]
+    fn should_pad_shortcut_column_to_gutter_width() {
+        // given - the default leader chord shown in the help popup
+        let keys = ";e";
+        // when
+        let column = shortcut_column(keys);
+        // then - two-space indent plus a 10-cell key field
+        assert_eq!(column, "  ;e        ");
+        assert_eq!(column.width(), 12);
+    }
+
+    #[test]
+    fn should_keep_a_separator_space_when_shortcut_overflows_gutter() {
+        // given - a chord built from two <space> labels blows past the gutter
+        let keys = "<space>h/<space>l";
+        // when
+        let column = shortcut_column(keys);
+        // then - nothing is dropped and the description stays detached
+        assert_eq!(column, "  <space>h/<space>l ");
+    }
+
     #[test]
     fn should_pad_highlighted_spans_to_exact_width() {
         // given - highlighted spans from the syntax highlighter (which strips