feat: add Nerd Font installation, Yazi file manager, and themed Yazi config

- Install JetBrainsMono Nerd Font for icons across all TUI tools
- Add Yazi as terminal file manager with themed config per colorscheme
- Add write_yazi_config() to all 5 theme files
- Theme switcher (archduino-theme) now also updates Yazi
- Add 'y' alias for yazi in shell config
- Update step numbering (9 -> 11 steps) and README

lib/scaffold.sh

@@ -1,7 +1,7 @@
 #!/bin/bash
 # Step 9: Project scaffolding tool + templates
 
-step "9/9 — Creating project scaffolding tool"
+step "11/11 — Creating project scaffolding tool"
 
 mkdir -p ~/.local/bin ~/.config/archduino/templates
 
@@ -215,6 +215,11 @@ info "Zellij updated"
 write_lazygit_config ~/.config/lazygit/config.yml
 info "Lazygit updated"
 
+# Yazi
+mkdir -p ~/.config/yazi
+write_yazi_config ~/.config/yazi/theme.toml
+info "Yazi updated"
+
 # NvChad
 NVIM_CFG="$HOME/.config/nvim"
 if [[ -f "$NVIM_CFG/lua/chadrc.lua" ]]; then