feat(variants): add Waveshare ESP32-S3-LR1121

ESP32-S3FH4R2 (4MB flash, 2MB PSRAM, native USB-CDC) with an LR1121.
Pins, the DIO5/DIO6 RF switch table and the 1.8 V TCXO follow the HF
schematic and Waveshare's examples. Envs: repeater, room server,
companion USB/BLE and KISS modem, all on min_spiffs so roles share one
partition layout.

Only RFO_HP_LF is wired (R4 on RFO_LP_LF is not fitted), so the new
opt-in LR1121_FORCE_HP_PA flag keeps RadioLib on the HP PA at <= 14 dBm,
where it would otherwise select the unconnected LP PA.

src/helpers/radiolib/CustomLR1121.h

@@ -36,6 +36,13 @@ class CustomLR1121 : public LR1121 {
       return len;
     }
     
+#ifdef LR1121_FORCE_HP_PA
+    // boards with only RFO_HP_LF wired: stop RadioLib switching to the LP PA at <= 14 dBm (2.4 GHz still uses the HF PA)
+    int16_t setOutputPower(int8_t power) override {
+      return LR1121::setOutputPower(power, true);
+    }
+#endif
+
     float getFreqMHz() const { return freqMHz; }
 
     int16_t setRxBoostedGainMode(bool en) {