Phase 2: Fix C++ memory leaks and add destructors

Co-authored-by: Genaker <9213670+Genaker@users.noreply.github.com>

lib/charts/StackedChart.cpp

@@ -10,7 +10,9 @@ size_t StackedChart::addChart(Chart *c)
     Chart **cc = new Chart *[charts_sz + 1];
     memcpy(cc, charts, charts_sz * sizeof(Chart *));
     cc[charts_sz] = c;
-    free(charts);
+    
+    // Use delete[] instead of free since we allocated with new[]
+    delete[] charts;
 
     c->reset(pos_x + c->pos_x, pos_y + c->pos_y, trim_w(c->pos_x, c->width, width),
              c->height);

lib/charts/charts.h

@@ -80,6 +80,13 @@ struct BarChart : ProgressChart, Listener
         memset(changed, 0, w * sizeof(bool));
     };
 
+    ~BarChart()
+    {
+        // Clean up dynamically allocated arrays
+        delete[] ys;
+        delete[] changed;
+    }
+
     void reset(uint16_t x, uint16_t y, uint16_t w, uint16_t h) override;
     void clear();
     int updatePoint(float x, float y) override;
@@ -122,6 +129,15 @@ struct StackedChart : Chart, Listener
     StackedChart(Display_t &d, uint16_t x, uint16_t y, uint16_t w, uint16_t h)
         : Chart(d, x, y, w, h), charts(NULL), charts_sz(0) {};
 
+    ~StackedChart()
+    {
+        // Clean up dynamically allocated chart array
+        if (charts != NULL)
+        {
+            delete[] charts;
+        }
+    }
+
     /*
      * addChart adds c to the StackedChart, treats pos_x and pos_y of the chart
      * as relative to this chart's origin, and trims width to fit. Adjust the

src/main.cpp

@@ -89,6 +89,9 @@ class MyServerCallbacks : public BLEServerCallbacks
     }
 };
 
+// Create static instance to avoid memory leak
+MyServerCallbacks serverCallbacks;
+
 #else
 #include <NimBLEDevice.h>
 
@@ -242,7 +245,7 @@ void initBT()
 #else
     BLEDevice::init("ESP32_RADAR");
     pServer = BLEDevice::createServer();
-    pServer->setCallbacks(new MyServerCallbacks());
+    pServer->setCallbacks(&serverCallbacks);  // Use static instance instead of new
 
     BLEService *pService = pServer->createService(SERVICE_UUID);