feat(fzf): use preview script in all workflows

Replace inline bat/head preview commands with the universal
preview script in the f() alias, file picker, and grep picker.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

home/.aliases

@@ -46,7 +46,7 @@ gdm() { local base="${1:-$(git symbolic-ref refs/remotes/origin/HEAD 2>/dev/null
 # fzf workflows
 gb() { local b; b="$(git branch --all --sort=-committerdate --format='%(refname:short)' | fzf --preview 'git log --oneline --color -20 {}')" && git checkout "${b#origin/}"; }
 glo() { git log --oneline --color --decorate | fzf --ansi --preview 'git show --color --stat {1}' --bind 'enter:become(echo {1})'; }
-f() { local f; f="$(fzf --preview 'head -100 {}')" && ${EDITOR:-vim} "$f"; }
+f() { local f; f="$(fzf --preview 'preview {}')" && ${EDITOR:-vim} "$f"; }
 
 if [[ -z "${CODESPACES:-}" ]]; then
 ssh() {

home/.zsh/widgets.zsh

@@ -62,7 +62,9 @@ _dots_load_keybindings() {
             rg --files --hidden --glob '!.git' 2>/dev/null | awk '{print " \t" $0}'
         } | awk -F'\t' '!seen[$2]++' \
           | fzf --ansi --delimiter='\t' --nth=2 \
-                --preview 'bat --color=always --style=numbers --line-range=:100 {2} 2>/dev/null || head -100 {2}')" \
+                --header 'enter=edit | ^v=preview' \
+                --preview 'preview {2}' \
+                --bind 'ctrl-v:execute(preview {2})')" \
           || { zle reset-prompt; return; }
         file="$(printf '%s' "$file" | cut -f2)"
         [[ -z "$file" ]] && { zle reset-prompt; return; }
@@ -117,7 +119,7 @@ _dots_load_keybindings() {
         local selection
         selection="$(rg --color=always --line-number --no-heading --hidden --glob '!.git' '' 2>/dev/null \
             | fzf --ansi --delimiter=: \
-                  --preview 'n={2}; n=${n:-1}; bat --color=always --style=numbers --highlight-line=$n --line-range=$((n>30?n-30:1)):$((n+30)) {1} 2>/dev/null || head -n $(( n + 30 )) {1} 2>/dev/null | tail -n 60' \
+                  --preview 'preview {1} {2}' \
                   --preview-window='right:60%')" || { zle -I; zle reset-prompt; return; }
         local file="${selection%%:*}"
         local line="${${selection#*:}%%:*}"