fix(setup): read skill names without a process per skill (#2120)

On Windows on ARM64, x64-emulated Git Bash intermittently deadlocks in MSYS2's
fork() emulation, and ./setup hung in the loops that read every SKILL.md name
through grep | sed | tr plus a basename (about four process starts per skill).
A sourced helper, bin/gstack-skill-name.sh, reads the name with a bash read
loop and no subshell; gstack-patch-names, setup's link and cleanup loops and
gstack-uninstall's inventory use it and parameter expansion instead of
basename. Codex links keep their directory names.

Co-authored-by: capy-ai[bot] <230910855+capy-ai[bot]@users.noreply.github.com>

bin/gstack-patch-names

@@ -8,13 +8,15 @@ DO_PREFIX="$2"
 
 # Normalize prefix arg
 case "$DO_PREFIX" in true|1) DO_PREFIX=1 ;; *) DO_PREFIX=0 ;; esac
+# Names are read with a bash builtin loop: no process per skill (#2120).
+. "$(dirname "$0")/gstack-skill-name.sh"
 
 PATCHED=0
 for skill_dir in "$GSTACK_DIR"/*/; do
   [ -f "$skill_dir/SKILL.md" ] || continue
-  dir_name="$(basename "$skill_dir")"
+  dir_name=${skill_dir%/}; dir_name=${dir_name##*/}
   [ "$dir_name" = "node_modules" ] && continue
-  cur=$(grep -m1 '^name:' "$skill_dir/SKILL.md" 2>/dev/null | sed 's/^name:[[:space:]]*//' | tr -d '[:space:]' || true)
+  gstack_skill_md_name "$skill_dir/SKILL.md"; cur=$GSTACK_SKILL_NAME
   [ -z "$cur" ] && continue
   [ "$cur" = "gstack" ] && continue  # never prefix root skill
   if [ "$DO_PREFIX" -eq 1 ]; then

bin/gstack-skill-name.sh

@@ -0,0 +1,21 @@
+# shellcheck shell=bash
+# gstack-skill-name.sh: sourced helper (bash 3.2). gstack_skill_md_name FILE
+# sets GSTACK_SKILL_NAME to the first column-0 "name:" line of FILE with every
+# whitespace character removed (CR included), or to "" when there is none or
+# FILE cannot be read. Always returns 0.
+#
+# It starts no process: no subshell, pipe or command substitution, and callers
+# must not wrap it in $( ). Setup reads ~55 names per run, and the
+# grep | sed | tr pipeline it replaces deadlocked MSYS2's fork() under x64
+# emulation on Windows ARM64 (#2120).
+gstack_skill_md_name() {
+  GSTACK_SKILL_NAME=
+  [ -f "$1" ] && [ -r "$1" ] || return 0
+  local _gsn_line
+  while IFS= read -r _gsn_line || [ -n "$_gsn_line" ]; do
+    case "$_gsn_line" in
+      name:*) _gsn_line=${_gsn_line#name:}; GSTACK_SKILL_NAME=${_gsn_line//[[:space:]]/}; return 0 ;;
+    esac
+  done < "$1"
+  return 0
+}

bin/gstack-uninstall

@@ -59,6 +59,9 @@ GSTACK_DIR="${GSTACK_DIR:-$(cd "$(dirname "$0")/.." && pwd)}"
 STATE_DIR="$HOME/.gstack"
 _STATE_DOC="https://github.com/garrytan/gstack/blob/main/docs/state-root.md"
 . "$(dirname "$0")/gstack-state-root.sh" 2>/dev/null || { echo "$0: cannot resolve the gstack state root: $(dirname "$0")/gstack-state-root.sh is missing. fix: reinstall with ./setup or /gstack-upgrade ($_STATE_DOC)" >&2; exit 1; }
+# Skill names without a process per skill (#2120); an older copy lacking the helper keeps the pipeline.
+. "$(dirname "$0")/gstack-skill-name.sh" 2>/dev/null \
+  || gstack_skill_md_name() { GSTACK_SKILL_NAME=$(grep -m1 '^name:' "$1" 2>/dev/null | sed 's/^name:[[:space:]]*//' | tr -d '[:space:]' || true); }
 gstack_state_root_select
 RESOLVED_ROOT="$_gstack_sr_root"
 RESOLVED_VAR="$_gstack_sr_var"
@@ -288,8 +291,8 @@ _INVENTORY=" _gstack-command connect-chrome gstack-connect-chrome "
 if [ -d "$GSTACK_DIR" ]; then
   for _SRC in "$GSTACK_DIR"/*/; do
     [ -f "$_SRC/SKILL.md" ] || continue
-    _SRC_NAME="$(basename "$_SRC")"
-    _FM_NAME=$(grep -m1 '^name:' "$_SRC/SKILL.md" 2>/dev/null | sed 's/^name:[[:space:]]*//' | tr -d '[:space:]' || true)
+    _SRC_NAME=${_SRC%/}; _SRC_NAME=${_SRC_NAME##*/}
+    gstack_skill_md_name "$_SRC/SKILL.md"; _FM_NAME=$GSTACK_SKILL_NAME
     for _N in "$_SRC_NAME" "$_FM_NAME"; do
       [ -n "$_N" ] || continue
       case "$_INVENTORY" in *" $_N "*) ;; *) _INVENTORY="$_INVENTORY$_N gstack-$_N " ;; esac