feat(config): add stacked layout icon to kitty tab bar)

dot_config/kitty/tab_bar.py

@@ -26,6 +26,7 @@ from typing import Any
 # (checked with `fc-list ":charset=<hex>:family=VictorMono Nerd Font Mono"`).
 FOLDER = '\uf07b'  # nf-fa-folder — the fallback: "a shell somewhere"
 EDITOR = '\ue62b'  # nf-custom-neovim
+STACKED = '\U000f0328'  # nf-md-layers — stack layout is hiding the tab's other panes
 
 ICONS: dict[str, str] = {
     # editors (label becomes the edited file, see EDITORS below)
@@ -112,6 +113,10 @@ _repo: dict[str, str] = {}
 
 
 def draw_title(data: dict[str, Any]) -> str:
+    return _title(data) + _stacked(data)
+
+
+def _title(data: dict[str, Any]) -> str:
     tab = data['tab']
     program = _program(_cmdlines(data['tab_id']), tab.active_exe)
     index = data['index']
@@ -127,6 +132,15 @@ def draw_title(data: dict[str, Any]) -> str:
     return f'{index} {icon} {_elide(label or data["title"])}'
 
 
+def _stacked(data: dict[str, Any]) -> str:
+    """` <layers icon> 3` when the stack layout (super+z) shows one of 3 panes, else ''.
+
+    kitty marks the tab bar dirty on every layout change, so toggling repaints this.
+    """
+    panes = data['num_window_groups']
+    return f' {STACKED} {panes}' if data['layout_name'] == 'stack' and panes > 1 else ''
+
+
 def _cmdlines(tab_id: int) -> list[list[str]]:
     """argv of every foreground process of the tab's active window.