feat: multi-instance active support, per-instance tool permissions, versioned release artifacts
- Add global settings (default_mode) and per-instance mode/allowed_tools
- ClientManager: lazy-init and cache OdooClient per instance ID
- MCP server: route tool calls to specified or active instance
- Enforce CRUD vs read_only permissions per instance
- Web UI: mode badge per instance, global mode selector
- release.yml: versioned artifact names (e.g. odoo-erp-mcp-windows-0.2.0.exe)
- Remove config.json from git tracking; add config.example.json template
- Change project license from GNU AGPL-3 to MIT License