Add getCodingRate() and getFreqMHz() to CustomLR1110/Wrapper

getCodingRate() returns codingRate+4 (RadioLib stores 1-4 internally,
expose as CR4/5-8 matching the rest of the codebase).
CustomLR1110Wrapper overrides both getCodingRate() and getFreqMHz() so
isJapanMode() and getMaxTextLen() work correctly on T1000-E.

src/helpers/radiolib/CustomLR1110.h

@@ -82,4 +82,5 @@ class CustomLR1110 : public LR1110 {
     }
 
     uint8_t getSpreadingFactor() const { return spreadingFactor; }
+    uint8_t getCodingRate() const { return this->codingRate + 4; }  // RadioLib stores 1-4, return 5-8
 };

src/helpers/radiolib/CustomLR1110Wrapper.h

@@ -43,6 +43,8 @@ public:
   float getLastSNR() const override { return ((CustomLR1110 *)_radio)->getSNR(); }
 
   uint8_t getSpreadingFactor() const override { return ((CustomLR1110 *)_radio)->getSpreadingFactor(); }
+  uint8_t getCodingRate() const override { return ((CustomLR1110 *)_radio)->getCodingRate(); }
+  float getFreqMHz() const override { return ((CustomLR1110 *)_radio)->getFreqMHz(); }
   
   bool setRxBoostedGainMode(bool en) override {
     return ((CustomLR1110 *)_radio)->setRxBoostedGainMode(en) == RADIOLIB_ERR_NONE;