Add LilyGO T-Beam 1W support (#8967)

* Add LilyGO T-Beam 1W support
- Add board definition and variant files for ESP32-S3 based T-Beam 1W
- Add RF95_FAN_EN support to SX126xInterface for PA cooling fan
- Add SX126X_PA_RAMP_US for configurable PA ramp time (800us for 1W PA)
- Configure RF switch: DIO2 for PA, GPIO 21 for LNA control

* Set TX_GAIN_LORA to 10dB per PR feedback (offset for 1W PA)

* Apply suggestion from @Copilot

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

---------

Co-authored-by: Ben Meadors <benmmeadors@gmail.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

src/mesh/SX126xInterface.cpp

@@ -62,6 +62,11 @@ template <typename T> bool SX126xInterface<T>::init()
     digitalWrite(LORA_PA_TX_EN, LOW);
 #endif
 
+#ifdef RF95_FAN_EN
+    digitalWrite(RF95_FAN_EN, HIGH);
+    pinMode(RF95_FAN_EN, OUTPUT);
+#endif
+
 #if ARCH_PORTDUINO
     tcxoVoltage = (float)portduino_config.dio3_tcxo_voltage / 1000;
     if (portduino_config.lora_sx126x_ant_sw_pin.pin != RADIOLIB_NC) {
@@ -85,6 +90,13 @@ template <typename T> bool SX126xInterface<T>::init()
         power = -9;
 
     int res = lora.begin(getFreq(), bw, sf, cr, syncWord, power, preambleLength, tcxoVoltage, useRegulatorLDO);
+
+#ifdef SX126X_PA_RAMP_US
+    // Set custom PA ramp time for boards requiring longer stabilization (e.g., T-Beam 1W needs >800us)
+    if (res == RADIOLIB_ERR_NONE) {
+        lora.setPaRampTime(SX126X_PA_RAMP_US);
+    }
+#endif
     // \todo Display actual typename of the adapter, not just `SX126x`
     LOG_INFO("SX126x init result %d", res);
     if (res == RADIOLIB_ERR_CHIP_NOT_FOUND || res == RADIOLIB_ERR_SPI_CMD_FAILED)