Add missing chart hover tooltips for CPU, Memory, and TempDB charts in Lite

Wire up ChartHoverHelper for the three Lite charts that were missing
tooltip support. Wait Stats, Perfmon, TempDB File I/O, and File I/O
charts already had this; CPU, Memory, and TempDB (by type) did not.

Closes #81

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: erikdarlingdata

Lite/Controls/ServerTab.xaml.cs

@@ -39,6 +39,9 @@ public partial class ServerTab : UserControl
     private List<SelectableItem> _perfmonCounterItems = new();
     private Helpers.ChartHoverHelper? _waitStatsHover;
     private Helpers.ChartHoverHelper? _perfmonHover;
+    private Helpers.ChartHoverHelper? _cpuHover;
+    private Helpers.ChartHoverHelper? _memoryHover;
+    private Helpers.ChartHoverHelper? _tempDbHover;
     private Helpers.ChartHoverHelper? _tempDbFileIoHover;
     private Helpers.ChartHoverHelper? _fileIoReadHover;
     private Helpers.ChartHoverHelper? _fileIoWriteHover;
@@ -129,6 +132,9 @@ public ServerTab(ServerConnection server, DuckDbInitializer duckDb, CredentialSe
         /* Chart hover tooltips */
         _waitStatsHover = new Helpers.ChartHoverHelper(WaitStatsChart, "ms/sec");
         _perfmonHover = new Helpers.ChartHoverHelper(PerfmonChart, "");
+        _cpuHover = new Helpers.ChartHoverHelper(CpuChart, "%");
+        _memoryHover = new Helpers.ChartHoverHelper(MemoryChart, "GB");
+        _tempDbHover = new Helpers.ChartHoverHelper(TempDbChart, "MB");
         _tempDbFileIoHover = new Helpers.ChartHoverHelper(TempDbFileIoChart, "ms");
         _fileIoReadHover = new Helpers.ChartHoverHelper(FileIoReadChart, "ms");
         _fileIoWriteHover = new Helpers.ChartHoverHelper(FileIoWriteChart, "ms");
@@ -589,6 +595,7 @@ private static string FormatMb(double mb)
     private void UpdateCpuChart(List<CpuUtilizationRow> data)
     {
         ClearChart(CpuChart);
+        _cpuHover?.Clear();
         ApplyDarkTheme(CpuChart);
 
         if (data.Count == 0) { CpuChart.Refresh(); return; }
@@ -600,10 +607,12 @@ private void UpdateCpuChart(List<CpuUtilizationRow> data)
         var sqlPlot = CpuChart.Plot.Add.Scatter(times, sqlCpu);
         sqlPlot.LegendText = "SQL Server";
         sqlPlot.Color = ScottPlot.Color.FromHex("#4FC3F7");
+        _cpuHover?.Add(sqlPlot, "SQL Server");
 
         var otherPlot = CpuChart.Plot.Add.Scatter(times, otherCpu);
         otherPlot.LegendText = "Other";
         otherPlot.Color = ScottPlot.Color.FromHex("#E57373");
+        _cpuHover?.Add(otherPlot, "Other");
 
         CpuChart.Plot.Axes.DateTimeTicksBottom();
         ReapplyAxisColors(CpuChart);
@@ -617,6 +626,7 @@ private void UpdateCpuChart(List<CpuUtilizationRow> data)
     private void UpdateMemoryChart(List<MemoryTrendPoint> data, List<MemoryTrendPoint> grantData)
     {
         ClearChart(MemoryChart);
+        _memoryHover?.Clear();
         ApplyDarkTheme(MemoryChart);
 
         if (data.Count == 0) { MemoryChart.Refresh(); return; }
@@ -629,15 +639,18 @@ private void UpdateMemoryChart(List<MemoryTrendPoint> data, List<MemoryTrendPoin
         var totalPlot = MemoryChart.Plot.Add.Scatter(times, totalMem);
         totalPlot.LegendText = "Total Server Memory";
         totalPlot.Color = ScottPlot.Color.FromHex("#4FC3F7");
+        _memoryHover?.Add(totalPlot, "Total Server Memory");
 
         var targetPlot = MemoryChart.Plot.Add.Scatter(times, targetMem);
         targetPlot.LegendText = "Target Memory";
         targetPlot.Color = ScottPlot.Colors.Gray;
         targetPlot.LineStyle.Pattern = LinePattern.Dashed;
+        _memoryHover?.Add(targetPlot, "Target Memory");
 
         var bpPlot = MemoryChart.Plot.Add.Scatter(times, bufferPool);
         bpPlot.LegendText = "Buffer Pool";
         bpPlot.Color = ScottPlot.Color.FromHex("#81C784");
+        _memoryHover?.Add(bpPlot, "Buffer Pool");
 
         /* Memory grants trend line — show zero line when no grant data */
         double[] grantTimes, grantMb;
@@ -655,6 +668,7 @@ private void UpdateMemoryChart(List<MemoryTrendPoint> data, List<MemoryTrendPoin
         var grantPlot = MemoryChart.Plot.Add.Scatter(grantTimes, grantMb);
         grantPlot.LegendText = "Memory Grants";
         grantPlot.Color = ScottPlot.Color.FromHex("#FFB74D");
+        _memoryHover?.Add(grantPlot, "Memory Grants");
 
         MemoryChart.Plot.Axes.DateTimeTicksBottom();
         ReapplyAxisColors(MemoryChart);
@@ -670,6 +684,7 @@ private void UpdateMemoryChart(List<MemoryTrendPoint> data, List<MemoryTrendPoin
     private void UpdateTempDbChart(List<TempDbRow> data)
     {
         ClearChart(TempDbChart);
+        _tempDbHover?.Clear();
         ApplyDarkTheme(TempDbChart);
 
         if (data.Count == 0) { TempDbChart.Refresh(); return; }
@@ -682,14 +697,17 @@ private void UpdateTempDbChart(List<TempDbRow> data)
         var userPlot = TempDbChart.Plot.Add.Scatter(times, userObj);
         userPlot.LegendText = "User Objects";
         userPlot.Color = ScottPlot.Color.FromHex("#4FC3F7");
+        _tempDbHover?.Add(userPlot, "User Objects");
 
         var internalPlot = TempDbChart.Plot.Add.Scatter(times, internalObj);
         internalPlot.LegendText = "Internal Objects";
         internalPlot.Color = ScottPlot.Color.FromHex("#FFD54F");
+        _tempDbHover?.Add(internalPlot, "Internal Objects");
 
         var vsPlot = TempDbChart.Plot.Add.Scatter(times, versionStore);
         vsPlot.LegendText = "Version Store";
         vsPlot.Color = ScottPlot.Color.FromHex("#81C784");
+        _tempDbHover?.Add(vsPlot, "Version Store");
 
         TempDbChart.Plot.Axes.DateTimeTicksBottom();
         ReapplyAxisColors(TempDbChart);