fix(zsh): apply zshellcheck lint fixes

- use [[ ]] over [ ], quote vars, shallow clone in zinit.zsh
- typeset -A instead of declare -A
- nullglob (N) and path array idiom in bin.zsh/default.zsh

zsh/.config/zsh/config/bin.zsh

@@ -16,8 +16,8 @@ if [[ ! -f "$MARKER_FILE" ]]; then
 
     for tool in $gnu_tools; do
         gnubin="/opt/homebrew/opt/$tool/libexec/gnubin"
-        if [ -d "$gnubin" ]; then
-            for bin in "$gnubin"/*; do
+        if [[ -d "$gnubin" ]]; then
+            for bin in "$gnubin"/*(N); do
                 ln -sf "$bin" "$XDG_BIN_HOME/$(basename "$bin")"
             done
         fi
@@ -33,10 +33,10 @@ local bin_paths=(
     "/opt/homebrew/opt/gnu-getopt/bin"
 )
 for bin_path in "${bin_paths[@]}"; do
-    if [ -d "$bin_path" ]; then
+    if [[ -d "$bin_path" ]]; then
         case ":$PATH:" in
             *":$bin_path:"*) ;;
-            *) PATH="$bin_path:$PATH" ;;
+            *) path=("$bin_path" $path) ;;
         esac
     fi
 done

zsh/.config/zsh/config/default.zsh

@@ -12,5 +12,5 @@ export STARSHIP_CONFIG="$XDG_CONFIG_HOME"/starship/starship.toml
 export PNPM_HOME="$HOME/.local/share/pnpm"
 case ":$PATH:" in
   *":$PNPM_HOME/bin:"*) ;;
-  *) export PATH="$PNPM_HOME/bin:$PATH" ;;
+  *) path=("$PNPM_HOME/bin" $path) ;;
 esac

zsh/.config/zsh/zinit.zsh

@@ -1,11 +1,11 @@
 #!/usr/bin/env zsh
 
 ZINIT_HOME="${XDG_DATA_HOME:-${HOME}/.local/share}/zinit/zinit.git"
-[ ! -d $ZINIT_HOME ] && mkdir -p "$(dirname $ZINIT_HOME)"
-[ ! -d $ZINIT_HOME/.git ] && git clone https://github.com/zdharma-continuum/zinit.git "$ZINIT_HOME"
+[[ ! -d "$ZINIT_HOME" ]] && mkdir -p "$(dirname "$ZINIT_HOME")"
+[[ ! -d "$ZINIT_HOME/.git" ]] && git clone --depth 1 https://github.com/zdharma-continuum/zinit.git "$ZINIT_HOME"
 
 # not to use aliases: zi or zini
-declare -A ZINIT
+typeset -A ZINIT
 ZINIT[NO_ALIASES]=1
 ZINIT[LIST_COMMAND]='lsd --tree'