feat(jade): create modular desktop environment

Rename xmonad/ to jade/ and restructure as a complete desktop environment
with hybrid NixOS and home-manager modules. This establishes jade as a
self-contained, gruvbox-themed DE that can eventually be extracted as a flake.

Changes:
- Create jade/ with NixOS module (WM, system packages, GTK theme)
- Create jade/home.nix for home-manager services (wezterm, picom, dunst)
- Move dmenu with gruvbox patches into jade/dmenu/
- Convert wezterm to pure Lua config with gruvbox-material colors
- Move xinitrc into jade/ directory
- Remove feh/scrot from global env (now in jade)
- Remove dmenu overlay from global overlays
- Simplify home-manager desktop features to just user apps

This follows the pattern of real DEs (GNOME, KDE) where system and user
configs are split across NixOS and home-manager modules.

home-manager/sajenim/features/cli/zsh.nix

@@ -1,4 +1,8 @@
-{pkgs, config, ...}: {
+{
+  pkgs,
+  config,
+  ...
+}: {
   imports = [
     ./direnv.nix
     ./starship.nix
@@ -47,10 +51,25 @@
     ];
 
     # Extra commands that should be added to '.zshrc'
-    initContent = ''
+    initContent = /* sh */ ''
       bindkey "^[[1;5C" forward-word
       bindkey "^[[1;5D" backward-word
       export PATH
+
+      # Auto-set wezterm tab title based on directory
+      chpwd() {
+        if [[ -d .git ]]; then
+          # Use git repo name
+          local repo=$(basename $(git rev-parse --show-toplevel 2>/dev/null))
+          wezterm cli set-tab-title "$repo" 2>/dev/null
+        elif [[ $(pwd) =~ "/home/sajenim/.repositories/personal/([^/]+)" ]]; then
+          # Use directory name for project dirs
+          wezterm cli set-tab-title "''${match[1]}" 2>/dev/null
+        fi
+      }
+
+      # Run once on shell startup
+      chpwd
     '';
   };
 }