Meshtastic support

**Describe the problem you have/What new integration you would like**
Support for Meshtastic Lora network and sx126x chips. Meshtastic provides a great, community-driven Lora broadcast network for sensor communications over long distances. Meshtastic already supports many ESP32-based chips and SX126x modems but lacks sensor support and customization similar to ESPHome.

**Please describe your use case for this integration and alternatives you've tried:**
If we could use the Meshtastic project for Lora to MQTT (an existing solution) to Home Assistant on the gateway side and ESPHome with the Meshtastic Lora network on the client side, we can achieve both flexibility and customization of both projects. This would make remote sensors easily and cheaply available to HomeAssistant.

**Additional context**

Start by reviewing the Meshtastic project, its support for ESP32 and SX126x hardware, and the existing Meshtastic LoRa-to-MQTT gateway approach described in the request. Compare those capabilities with ESPHome’s sensor and customization model. Done means a defined client-side integration that can communicate over the Meshtastic network and interoperate with the gateway path to Home Assistant.

Written by the indexing model from the issue text.