- Updated `shelly` class to support POST request handling (`sendPostRequest`) and server URL validation.
- Adjusted `shelly_device_state` to handle object-based `status` and `settings`, adding a `populate` method for data initialization.
- Added `shelly_device_switch` helper to manage switching operations via Shelly API.
- Removed unused `api_url` property in `shelly` class.
- Modified `shelly_i` interface with definitions for `requireValidServerUrl` and `sendPostRequest`.
- Added `shelly` class to manage API operations, handle requests, and validate configurations.
- Introduced `shelly_i` interface and supporting helpers: `shelly_device_state`, `shelly_request_body_get_states`, and `shelly_response_body_get_states`.
- Created new routes for fetching and updating Shelly configurations (`/shelly/config`).
- Added Shelly module configurations: `enabled`, `secret_key`, and `server_url`.
- Implemented `shelly_c` for module setup and configuration handling.
- Integrated Shelly initialization in `index.php`.