Add Support for Multiple Isolated Instances (Custom Manager Name / Workspace)

Feature request: allow running multiple HiClaw instances on the same host.

The install script currently hardcodes the manager container name (`hiclaw-manager`) and default workspace, which causes conflicts when installing a second instance, even with different ports.

It would help to support either:
- an install wizard prompt (instance name), or
- environment variables (e.g. HICLAW_MANAGER_NAME, HICLAW_WORKSPACE_DIR)

These should be used to control container name, workspace path, and related resources.

This would enable clean multi-instance setups without manual renaming or custom docker-compose.