fix(claude): skip migration when native binary exists

- guide.sh: Check for working native binary at ~/.local/bin/claude
  before triggering full migration; if exists, just clean up stale
  npm/nvm versions
- install_claude.sh: Add source guard to allow cleanup_npm_versions
  to be called without triggering main install logic

This prevents repeated migration attempts when both native and npm
installations exist, and handles the case where Claude Code may
self-reinstall via npm.

Author: CybotTM

scripts/guide.sh

@@ -177,8 +177,28 @@ process_tool() {
   local auto_update="$(config_get_auto_update "$catalog_tool")"
 
   # Check if migration needed (deprecated install method)
+  # But skip migration if native binary already exists and works
   local needs_migration=""
   if [ "$tool" = "claude" ] && { [ "$method" = "nvm" ] || [ "$method" = "npm" ]; }; then
+    # Check if native binary exists and works
+    if [ -x "$HOME/.local/bin/claude" ]; then
+      local native_ver
+      native_ver=$("$HOME/.local/bin/claude" --version 2>/dev/null | grep -oE '[0-9]+\.[0-9]+\.[0-9]+' | head -1 || true)
+      if [ -n "$native_ver" ]; then
+        # Native exists - just clean up stale nvm, don't trigger full migration
+        printf "\n==> %s %s\n" "✅" "$display"
+        printf "    installed: %s (native at ~/.local/bin/claude)\n" "$native_ver"
+        printf "    Cleaning up stale npm/nvm installation...\n"
+        # Source cleanup function and run it
+        if [ -f "$ROOT/scripts/install_claude.sh" ]; then
+          (
+            source "$ROOT/scripts/install_claude.sh" 2>/dev/null
+            cleanup_npm_versions 2>/dev/null
+          ) || true
+        fi
+        return 0
+      fi
+    fi
     needs_migration="true"
   fi
 

scripts/install_claude.sh

@@ -340,10 +340,14 @@ uninstall_claude() {
   fi
 }
 
-case "$ACTION" in
-  install) install_claude ;;
-  update|upgrade) upgrade_claude ;;
-  uninstall) uninstall_claude ;;
-  reconcile) install_claude ;;
-  *) echo "Usage: $0 {install|update|upgrade|uninstall|reconcile}" ; exit 2 ;;
-esac
+# Only run main logic when executed directly, not when sourced
+# This allows other scripts to source this file for cleanup_npm_versions
+if [[ "${BASH_SOURCE[0]}" == "${0}" ]]; then
+  case "$ACTION" in
+    install) install_claude ;;
+    update|upgrade) upgrade_claude ;;
+    uninstall) uninstall_claude ;;
+    reconcile) install_claude ;;
+    *) echo "Usage: $0 {install|update|upgrade|uninstall|reconcile}" ; exit 2 ;;
+  esac
+fi