refactor(ui): enhance chart destruction and instance management

Improve robustness of chart updates in dashboard components by adding
force destroy checks across canvas properties, component state, and
Chart.js registry to prevent memory leaks and instance conflicts.
Save new chart instances to both canvas and component for better tracking.

public/js/components/dashboard/charts.js

@@ -135,16 +135,6 @@ window.DashboardCharts.createDataset = function (label, data, color, canvas) {
  * @param {object} component - Dashboard component instance
  */
 window.DashboardCharts.updateCharts = function (component) {
-  // Safely destroy existing chart instance FIRST
-  if (component.charts.quotaDistribution) {
-    try {
-      component.charts.quotaDistribution.destroy();
-    } catch (e) {
-      console.error("Failed to destroy quota chart:", e);
-    }
-    component.charts.quotaDistribution = null;
-  }
-
   const canvas = document.getElementById("quotaChart");
 
   // Safety checks
@@ -152,6 +142,33 @@ window.DashboardCharts.updateCharts = function (component) {
     console.debug("quotaChart canvas not found");
     return;
   }
+
+  // FORCE DESTROY: Check for existing chart on the canvas element property
+  // This handles cases where Component state is lost but DOM persists
+  if (canvas._chartInstance) {
+    console.debug("Destroying existing quota chart from canvas property");
+    try {
+        canvas._chartInstance.destroy();
+    } catch(e) { console.warn(e); }
+    canvas._chartInstance = null;
+  }
+  
+  // Also check component state as backup
+  if (component.charts.quotaDistribution) {
+     try {
+         component.charts.quotaDistribution.destroy();
+     } catch(e) { }
+     component.charts.quotaDistribution = null;
+  }
+  
+  // Also try Chart.js registry
+  if (typeof Chart !== "undefined" && Chart.getChart) {
+      const regChart = Chart.getChart(canvas);
+      if (regChart) {
+          try { regChart.destroy(); } catch(e) {}
+      }
+  }
+
   if (typeof Chart === "undefined") {
     console.warn("Chart.js not loaded");
     return;
@@ -250,8 +267,10 @@ window.DashboardCharts.updateCharts = function (component) {
     labels.push(depletedLabel);
   });
 
+  // Create Chart
   try {
-    component.charts.quotaDistribution = new Chart(canvas, {
+    const newChart = new Chart(canvas, {
+       // ... config
        type: "doughnut",
        data: {
          labels: labels,
@@ -283,6 +302,11 @@ window.DashboardCharts.updateCharts = function (component) {
          },
        },
     });
+    
+    // SAVE INSTANCE TO CANVAS AND COMPONENT
+    canvas._chartInstance = newChart;
+    component.charts.quotaDistribution = newChart;
+    
   } catch (e) {
     console.error("Failed to create quota chart:", e);
   }
@@ -302,28 +326,46 @@ window.DashboardCharts.updateTrendChart = function (component) {
 
   console.log("[updateTrendChart] Starting update...");
 
-  // Safely destroy existing chart instance FIRST
+  const canvas = document.getElementById("usageTrendChart");
-  if (component.charts.usageTrend) {
+  
-    console.log("[updateTrendChart] Destroying existing chart");
+  // FORCE DESTROY: Check for existing chart on the canvas element property
+  if (canvas) {
+      if (canvas._chartInstance) {
+        console.debug("Destroying existing trend chart from canvas property");
         try {
-      // Stop all animations before destroying to prevent null context errors
+            canvas._chartInstance.stop();
-      component.charts.usageTrend.stop();
+            canvas._chartInstance.destroy();
-      component.charts.usageTrend.destroy();
+        } catch(e) { console.warn(e); }
-    } catch (e) {
+        canvas._chartInstance = null;
-      console.error("[updateTrendChart] Failed to destroy chart:", e);
-    }
-    component.charts.usageTrend = null;
       }
       
-  const canvas = document.getElementById("usageTrendChart");
+      // Also try Chart.js registry
+      if (typeof Chart !== "undefined" && Chart.getChart) {
+          const regChart = Chart.getChart(canvas);
+          if (regChart) {
+              try { regChart.stop(); regChart.destroy(); } catch(e) {}
+          }
+      }
+  }
+
+  // Also check component state
+  if (component.charts.usageTrend) {
+    try {
+      component.charts.usageTrend.stop();
+      component.charts.usageTrend.destroy();
+    } catch (e) { }
+    component.charts.usageTrend = null;
+  }
 
   // Safety checks
   if (!canvas) {
     console.error("[updateTrendChart] Canvas not found in DOM!");
+    _trendChartUpdateLock = false; // Release lock!
     return;
   }
   if (typeof Chart === "undefined") {
     console.error("[updateTrendChart] Chart.js not loaded");
+    _trendChartUpdateLock = false; // Release lock!
     return;
   }
 
@@ -476,7 +518,7 @@ window.DashboardCharts.updateTrendChart = function (component) {
   }
 
   try {
-    component.charts.usageTrend = new Chart(canvas, {
+    const newChart = new Chart(canvas, {
       type: "line",
       data: { labels, datasets },
       options: {
@@ -533,6 +575,11 @@ window.DashboardCharts.updateTrendChart = function (component) {
         },
       },
     });
+    
+    // SAVE INSTANCE
+    canvas._chartInstance = newChart;
+    component.charts.usageTrend = newChart;
+
   } catch (e) {
     console.error("Failed to create trend chart:", e);
   } finally {