fix: review fixes — ETHOS.md, runtime root, repo-local guard, kiro assets, upgrade paths

Paranoid 4-pass review found 7 issues, all fixed:
- Add ETHOS.md to create_codex_runtime_root
- Clean old real dirs (not just symlinks) on upgrade
- Skip runtime root for repo-local installs (prevent self-referential symlinks)
- Add review/, ETHOS.md, gstack-upgrade/ to Kiro install
- Update gstack-upgrade to detect ~/.gstack/repos/ and .agents/skills/
- Guard --host without value from silent exit
- Fix Kiro sed patterns + timeout instruction in gen-skill-docs.ts

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

setup

@@ -24,7 +24,7 @@ esac
 HOST="claude"
 while [ $# -gt 0 ]; do
   case "$1" in
-    --host) HOST="$2"; shift 2 ;;
+    --host) [ -z "$2" ] && echo "Missing value for --host (expected claude, codex, kiro, or auto)" >&2 && exit 1; HOST="$2"; shift 2 ;;
     --host=*) HOST="${1#--host=}"; shift ;;
     *) shift ;;
   esac
@@ -293,6 +293,10 @@ create_codex_runtime_root() {
 
   if [ -L "$codex_gstack" ]; then
     rm -f "$codex_gstack"
+  elif [ -d "$codex_gstack" ] && [ "$codex_gstack" != "$gstack_dir" ]; then
+    # Old direct installs left a real directory here with stale source skills.
+    # Remove it so we start fresh with only the minimal runtime assets.
+    rm -rf "$codex_gstack"
   fi
 
   mkdir -p "$codex_gstack" "$codex_gstack/browse" "$codex_gstack/gstack-upgrade" "$codex_gstack/review"
@@ -318,6 +322,10 @@ create_codex_runtime_root() {
       ln -snf "$gstack_dir/review/$f" "$codex_gstack/review/$f"
     fi
   done
+  # ETHOS.md — referenced by "Search Before Building" in all skill preambles
+  if [ -f "$gstack_dir/ETHOS.md" ]; then
+    ln -snf "$gstack_dir/ETHOS.md" "$codex_gstack/ETHOS.md"
+  fi
 }
 
 # 4. Install for Claude (default)
@@ -348,7 +356,11 @@ if [ "$INSTALL_CODEX" -eq 1 ]; then
   fi
   mkdir -p "$CODEX_SKILLS"
 
-  create_codex_runtime_root "$SOURCE_GSTACK_DIR" "$CODEX_GSTACK"
+  # Skip runtime root creation for repo-local installs — the checkout IS the runtime root.
+  # create_codex_runtime_root would create self-referential symlinks (bin → bin, etc.).
+  if [ "$CODEX_REPO_LOCAL" -eq 0 ]; then
+    create_codex_runtime_root "$SOURCE_GSTACK_DIR" "$CODEX_GSTACK"
+  fi
   # Install generated Codex-format skills (not Claude source dirs)
   link_codex_skill_dirs "$SOURCE_GSTACK_DIR" "$CODEX_SKILLS"
 
@@ -367,9 +379,24 @@ if [ "$INSTALL_KIRO" -eq 1 ]; then
   KIRO_GSTACK="$KIRO_SKILLS/gstack"
   # Remove old whole-dir symlink from previous installs
   [ -L "$KIRO_GSTACK" ] && rm -f "$KIRO_GSTACK"
-  mkdir -p "$KIRO_GSTACK"
+  mkdir -p "$KIRO_GSTACK" "$KIRO_GSTACK/browse" "$KIRO_GSTACK/gstack-upgrade" "$KIRO_GSTACK/review"
   ln -snf "$SOURCE_GSTACK_DIR/bin" "$KIRO_GSTACK/bin"
-  ln -snf "$SOURCE_GSTACK_DIR/browse" "$KIRO_GSTACK/browse"
+  ln -snf "$SOURCE_GSTACK_DIR/browse/dist" "$KIRO_GSTACK/browse/dist"
+  ln -snf "$SOURCE_GSTACK_DIR/browse/bin" "$KIRO_GSTACK/browse/bin"
+  # ETHOS.md — referenced by "Search Before Building" in all skill preambles
+  if [ -f "$SOURCE_GSTACK_DIR/ETHOS.md" ]; then
+    ln -snf "$SOURCE_GSTACK_DIR/ETHOS.md" "$KIRO_GSTACK/ETHOS.md"
+  fi
+  # gstack-upgrade skill
+  if [ -f "$AGENTS_DIR/gstack-upgrade/SKILL.md" ]; then
+    ln -snf "$AGENTS_DIR/gstack-upgrade/SKILL.md" "$KIRO_GSTACK/gstack-upgrade/SKILL.md"
+  fi
+  # Review runtime assets (individual files, not whole dir)
+  for f in checklist.md design-checklist.md greptile-triage.md TODOS-format.md; do
+    if [ -f "$SOURCE_GSTACK_DIR/review/$f" ]; then
+      ln -snf "$SOURCE_GSTACK_DIR/review/$f" "$KIRO_GSTACK/review/$f"
+    fi
+  done
 
   # Rewrite root SKILL.md paths for Kiro
   sed -e "s|~/.claude/skills/gstack|~/.kiro/skills/gstack|g" \
@@ -385,10 +412,11 @@ if [ "$INSTALL_KIRO" -eq 1 ]; then
       skill_name="$(basename "$skill_dir")"
       target_dir="$KIRO_SKILLS/$skill_name"
       mkdir -p "$target_dir"
-      sed -e "s|~/.codex/skills/gstack|~/.kiro/skills/gstack|g" \
+      # Generated Codex skills use $HOME/.codex (not ~/), plus $GSTACK_ROOT variables.
+      # Rewrite the default GSTACK_ROOT value and any remaining literal paths.
+      sed -e 's|\$HOME/.codex/skills/gstack|$HOME/.kiro/skills/gstack|g' \
+          -e "s|~/.codex/skills/gstack|~/.kiro/skills/gstack|g" \
           -e "s|~/.claude/skills/gstack|~/.kiro/skills/gstack|g" \
-          -e "s|\.agents/skills/gstack|.kiro/skills/gstack|g" \
-          -e "s|\.agents/skills|.kiro/skills|g" \
           "$skill_dir/SKILL.md" > "$target_dir/SKILL.md"
     done
     echo "gstack ready (kiro)."