feat: add Gemini skill integration and multi-user AI setup

tools/install_ai_integrations.py

@@ -0,0 +1,48 @@
+#!/usr/bin/env python3
+"""Cross-platform installer for ServerManager AI integrations.
+
+Supports Claude (/ssh), Codex (server-manager), and Gemini (server-manager)
+for the current user, a target home, or all discovered user homes.
+"""
+
+from __future__ import annotations
+
+import argparse
+import os
+import sys
+from pathlib import Path
+
+PROJECT_ROOT = Path(__file__).resolve().parents[1]
+if str(PROJECT_ROOT) not in sys.path:
+    sys.path.insert(0, str(PROJECT_ROOT))
+
+from core.claude_setup import install_all  # noqa: E402
+
+
+def parse_args() -> argparse.Namespace:
+    p = argparse.ArgumentParser(description="Install ServerManager AI integrations")
+    p.add_argument("--target-home", help="Install into this home directory instead of the current user")
+    p.add_argument("--all-users", action="store_true", help="Install to all discovered user homes on this system")
+    return p.parse_args()
+
+
+def main() -> int:
+    args = parse_args()
+
+    if args.target_home and args.all_users:
+        print("error: --target-home and --all-users are mutually exclusive", file=sys.stderr)
+        return 2
+
+    if args.target_home:
+        os.environ["SERVER_MANAGER_TARGET_HOME"] = os.path.abspath(os.path.expanduser(args.target_home))
+
+    if args.all_users:
+        os.environ["SERVER_MANAGER_INSTALL_ALL_USERS"] = "1"
+
+    for line in install_all():
+        print(line)
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())