Noise floor (#9347)

* add noise floor

* Sliding window noise floor

* Add getCurrentRSSI() to SimRadio for noise floor support

* Remove sendLocalStatsToPhone call from runOnce

* Change noise floor to int32_t type

* Use int32_t for RSSI sample storage in noise floor

* Remove float cast from noise floor assignment

* Fix Copilot review issues: fix noise floor logic, types, and null pointer

- Use robust busyTx/busyRx checks instead of simple isReceiving check
- Initialize noiseFloorSamples to NOISE_FLOOR_MIN instead of 0
- Move noise_floor assignment inside null check to prevent potential crash
- Change getNoiseFloor() and getAverageNoiseFloor() to return int32_t
- Fix RSSI validation to check for positive values (rssi > 0)
- Fix format specifier from %.1f to %d for int32_t
- Update comments to accurately reflect the sampling logic

* Fix RSSI condition to include zero value

* Change noise floor initialization to zero

* Disable noise floor for LR11x0 chips: getRSSI(bool) unsupported

* Remove updateNoiseFloor call from onNotify to avoid radio queue overflow

Per PR review feedback, calling updateNoiseFloor() in onNotify() for every
ISR event (ISR_TX, ISR_RX, TRANSMIT_DELAY_COMPLETED) can cause the LoRa
radio queue to get full. The noise floor sampling still happens in
startReceive() and after transmitting.

* fix lr11x0 current rssi

* Address noise floor review comments

* Address Copilot SimRadio noise floor comments

* Fix RadioLibInterface formatting

---------

Co-authored-by: Ben Meadors <benmmeadors@gmail.com>
Co-authored-by: Jonathan Bennett <jbennett@incomsystems.biz>

src/platform/portduino/SimRadio.cpp

@@ -362,4 +362,10 @@ uint32_t SimRadio::getPacketTime(uint32_t pl, bool received)
 
     uint32_t msecs = tPacket * 1000;
     return msecs;
+}
+
+int16_t SimRadio::getCurrentRSSI()
+{
+    // Simulated radio - return a reasonable default noise floor
+    return -120;
 }

src/platform/portduino/SimRadio.h

@@ -48,6 +48,8 @@ class SimRadio : public RadioInterface, protected concurrency::NotifiedWorkerThr
     // Convert Compressed_msg to normal msg and receive it
     void unpackAndReceive(meshtastic_MeshPacket &p);
 
+    int16_t getCurrentRSSI() override;
+
     /**
      * Debugging counts
      */
@@ -93,4 +95,4 @@ class SimRadio : public RadioInterface, protected concurrency::NotifiedWorkerThr
     virtual uint32_t getPacketTime(uint32_t pl, bool received = false) override;
 };
 
-extern SimRadio *simRadio;
+extern SimRadio *simRadio;