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>

variants/esp32s3/t-beam-1w/platformio.ini

@@ -0,0 +1,14 @@
+; LilyGo T-Beam-1W (1 Watt LoRa with external PA)
+[env:t-beam-1w]
+extends = esp32s3_base
+board = t-beam-1w
+board_build.partitions = default_8MB.csv
+board_check = true
+
+lib_deps =
+  ${esp32s3_base.lib_deps}
+
+build_flags = 
+  ${esp32s3_base.build_flags} 
+  -I variants/esp32s3/t-beam-1w
+  -D T_BEAM_1W