Merge remote-tracking branch 'origin/main' into garrytan/resolver-factoring

# Conflicts:
#	CHANGELOG.md
#	investigate/SKILL.md
#	investigate/SKILL.md.tmpl
#	office-hours/SKILL.md
#	office-hours/SKILL.md.tmpl
#	ship/SKILL.md
#	ship/SKILL.md.tmpl

bin/gstack-config

@@ -77,6 +77,11 @@ case "${1:-}" in
     else
       echo "${KEY}: ${VALUE}" >> "$CONFIG_FILE"
     fi
+    # Auto-relink skills when prefix setting changes (skip during setup to avoid recursive call)
+    if [ "$KEY" = "skill_prefix" ] && [ -z "${GSTACK_SETUP_RUNNING:-}" ]; then
+      GSTACK_RELINK="$(dirname "$0")/gstack-relink"
+      [ -x "$GSTACK_RELINK" ] && "$GSTACK_RELINK" || true
+    fi
     ;;
   list)
     cat "$CONFIG_FILE" 2>/dev/null || true

bin/gstack-open-url

@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+# gstack-open-url — cross-platform URL opener
+#
+# Usage: gstack-open-url <url>
+set -euo pipefail
+
+URL="${1:?Usage: gstack-open-url <url>}"
+
+case "$(uname -s)" in
+  Darwin)  open "$URL" ;;
+  Linux)   xdg-open "$URL" 2>/dev/null || echo "$URL" ;;
+  MINGW*|MSYS*|CYGWIN*) start "$URL" ;;
+  *)       echo "$URL" ;;
+esac

bin/gstack-relink

@@ -0,0 +1,73 @@
+#!/usr/bin/env bash
+# gstack-relink — re-create skill symlinks based on skill_prefix config
+#
+# Usage:
+#   gstack-relink
+#
+# Env overrides (for testing):
+#   GSTACK_STATE_DIR   — override ~/.gstack state directory
+#   GSTACK_INSTALL_DIR — override gstack install directory
+#   GSTACK_SKILLS_DIR  — override target skills directory
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+GSTACK_CONFIG="${SCRIPT_DIR}/gstack-config"
+
+# Detect install dir
+INSTALL_DIR="${GSTACK_INSTALL_DIR:-}"
+if [ -z "$INSTALL_DIR" ]; then
+  if [ -d "$HOME/.claude/skills/gstack" ]; then
+    INSTALL_DIR="$HOME/.claude/skills/gstack"
+  elif [ -d "${SCRIPT_DIR}/.." ] && [ -f "${SCRIPT_DIR}/../setup" ]; then
+    INSTALL_DIR="$(cd "${SCRIPT_DIR}/.." && pwd)"
+  fi
+fi
+
+if [ -z "$INSTALL_DIR" ] || [ ! -d "$INSTALL_DIR" ]; then
+  echo "Error: gstack install directory not found." >&2
+  echo "Run: cd ~/.claude/skills/gstack && ./setup" >&2
+  exit 1
+fi
+
+# Detect target skills dir
+SKILLS_DIR="${GSTACK_SKILLS_DIR:-$(dirname "$INSTALL_DIR")}"
+[ -d "$SKILLS_DIR" ] || mkdir -p "$SKILLS_DIR"
+
+# Read prefix setting
+PREFIX=$("$GSTACK_CONFIG" get skill_prefix 2>/dev/null || echo "false")
+
+# Discover skills (directories with SKILL.md, excluding meta dirs)
+SKILL_COUNT=0
+for skill_dir in "$INSTALL_DIR"/*/; do
+  [ -d "$skill_dir" ] || continue
+  skill=$(basename "$skill_dir")
+  # Skip non-skill directories
+  case "$skill" in bin|browse|design|docs|extension|lib|node_modules|scripts|test|.git|.github) continue ;; esac
+  [ -f "$skill_dir/SKILL.md" ] || continue
+
+  if [ "$PREFIX" = "true" ]; then
+    # Don't double-prefix directories already named gstack-*
+    case "$skill" in
+      gstack-*) link_name="$skill" ;;
+      *)        link_name="gstack-$skill" ;;
+    esac
+    ln -sfn "$INSTALL_DIR/$skill" "$SKILLS_DIR/$link_name"
+    # Remove old flat symlink if it exists (and isn't the same as the new link)
+    [ "$link_name" != "$skill" ] && [ -L "$SKILLS_DIR/$skill" ] && rm -f "$SKILLS_DIR/$skill"
+  else
+    # Create flat symlink, remove gstack-* if exists
+    ln -sfn "$INSTALL_DIR/$skill" "$SKILLS_DIR/$skill"
+    # Don't remove gstack-* dirs that are their real name (e.g., gstack-upgrade)
+    case "$skill" in
+      gstack-*) ;; # Already the real name, no old prefixed link to clean
+      *)        [ -L "$SKILLS_DIR/gstack-$skill" ] && rm -f "$SKILLS_DIR/gstack-$skill" ;;
+    esac
+  fi
+  SKILL_COUNT=$((SKILL_COUNT + 1))
+done
+
+if [ "$PREFIX" = "true" ]; then
+  echo "Relinked $SKILL_COUNT skills as gstack-*"
+else
+  echo "Relinked $SKILL_COUNT skills as flat names"
+fi