fix(sx126x): let CalibrateImage settle before re-applying RX registers in resetAGC()

src/mesh/SX126xInterface.cpp

@@ -569,6 +569,10 @@ template <typename T> void SX126xInterface<T>::resetAGC()
     // 5. Re-calibrate image rejection for actual operating frequency
     //    Calibrate(0x7F) defaults to 902-928 MHz which is wrong for other regions.
     lora.calibrateImage(getFreq());
+    // 6. CalibrateImage keeps working internally after it returns, and BUSY does not
+    //    stay asserted for it; a register write in that window fails write-verify
+    //    (RADIOLIB_ERR_SPI_WRITE_FAILED) and stalls the chip.
+    module.hal->delay(50);
 
     // Re-apply settings that calibration may have reset
 
@@ -592,7 +596,7 @@ template <typename T> void SX126xInterface<T>::resetAGC()
         LOG_WARN("SX126x resetAGC: 0x8B5 RX patch re-apply failed");
     }
 
-    // 6. Resume receiving
+    // 7. Resume receiving
     startReceive();
 }