fix(ux): improve fzf picker discoverability and empty state

- doctor: add shell integration check so users know they need
  eval "$(git gtr init <shell>)" in addition to installing fzf
- gtr cd: skip fzf and show guidance when no worktrees exist
  instead of launching picker with only the main repo listed

Author: helizaga

lib/commands/doctor.sh

@@ -114,11 +114,26 @@ cmd_doctor() {
 
   # Check fzf (optional, for interactive picker)
   if command -v fzf >/dev/null 2>&1; then
-    echo "[OK] fzf: $(fzf --version 2>/dev/null | awk '{print $1}') (interactive picker available)"
+    echo "[OK] fzf: $(fzf --version 2>/dev/null | awk '{print $1}') (interactive picker: gtr cd)"
   else
     echo "[i] fzf: not found (install for interactive picker: gtr cd)"
   fi
 
+  # Check shell integration (required for gtr cd)
+  local _shell_name _rc_file
+  _shell_name="$(basename "${SHELL:-bash}")"
+  case "$_shell_name" in
+    zsh)  _rc_file="$HOME/.zshrc" ;;
+    bash) _rc_file="$HOME/.bashrc" ;;
+    fish) _rc_file="$HOME/.config/fish/config.fish" ;;
+    *)    _rc_file="" ;;
+  esac
+  if [ -n "$_rc_file" ] && [ -f "$_rc_file" ] && grep -q 'git gtr init' "$_rc_file" 2>/dev/null; then
+    echo "[OK] Shell integration: loaded (gtr cd available)"
+  else
+    echo "[i] Shell integration: eval \"\$(git gtr init $_shell_name)\" in ${_rc_file##*/} for gtr cd"
+  fi
+
   echo ""
   if [ "$issues" -eq 0 ]; then
     echo "Everything looks good!"

lib/commands/init.sh

@@ -83,8 +83,14 @@ __FUNC__() {
     shift
     local dir
     if [ "$#" -eq 0 ] && command -v fzf >/dev/null 2>&1; then
+      local _gtr_porcelain
+      _gtr_porcelain="$(command git gtr list --porcelain)"
+      if [ "$(printf '%s\n' "$_gtr_porcelain" | wc -l)" -le 1 ]; then
+        echo "No worktrees to pick from. Create one with: git gtr new <branch>" >&2
+        return 0
+      fi
       local _gtr_selection
-      _gtr_selection="$(command git gtr list --porcelain | fzf \
+      _gtr_selection="$(printf '%s\n' "$_gtr_porcelain" | fzf \
         --delimiter=$'\t' \
         --with-nth=2 \
         --ansi \
@@ -183,8 +189,14 @@ __FUNC__() {
     shift
     local dir
     if [ "$#" -eq 0 ] && command -v fzf >/dev/null 2>&1; then
+      local _gtr_porcelain
+      _gtr_porcelain="$(command git gtr list --porcelain)"
+      if [ "$(printf '%s\n' "$_gtr_porcelain" | wc -l)" -le 1 ]; then
+        echo "No worktrees to pick from. Create one with: git gtr new <branch>" >&2
+        return 0
+      fi
       local _gtr_selection
-      _gtr_selection="$(command git gtr list --porcelain | fzf \
+      _gtr_selection="$(printf '%s\n' "$_gtr_porcelain" | fzf \
         --delimiter=$'\t' \
         --with-nth=2 \
         --ansi \
@@ -287,7 +299,12 @@ function __FUNC__
   if test (count $argv) -gt 0; and test "$argv[1]" = "cd"
     set -l dir
     if test (count $argv) -eq 1; and type -q fzf
-      set -l _gtr_selection (command git gtr list --porcelain | fzf \
+      set -l _gtr_porcelain (command git gtr list --porcelain)
+      if test (count $_gtr_porcelain) -le 1
+        echo "No worktrees to pick from. Create one with: git gtr new <branch>" >&2
+        return 0
+      end
+      set -l _gtr_selection (printf '%s\n' $_gtr_porcelain | fzf \
         --delimiter=\t \
         --with-nth=2 \
         --ansi \