fix(gui): eliminate GDI/resource leaks + harden crash log diagnostics

AppIcons.cs: dispose inline Pen (DrawUpIcon) and SolidBrush (DrawActivityIcon);
  dispose all bitmaps in InvalidateCache() to prevent GDI handle accumulation.
TweakBrowserPanel.cs: add Dispose override for _debounce timer.
MainForm.Designer.cs: dispose non-container-managed resources
  (_searchDebounceTimer, _profileScheduleTimer, _catScoreTip, _listItemTip, _cts).
MainForm.cs: unsubscribe sidebar/treeview events in OnFormClosing.
BasePackageManagerDialog.cs: dispose CancellationTokenSource on FormClosed.
RoundedPanel.cs: cache Region and only recreate on size change (was per-paint);
  add Dispose override for cached Region.
Program.cs: expand crash report with GC generation counts, heap size,
  finalizer queue depth, thread pool stats, and loaded assembly list.
AppIconsTests: update InvalidateCache test to verify bitmaps ARE disposed.

Total: 7,189 tweaks, 3,165 tests (0 failures)

Author: RajwanYair

src/RegiLattice.GUI/AppIcons.cs

@@ -88,16 +88,16 @@ internal static Bitmap MenuBitmap(string key, Action<Graphics, int> draw)
 
     /// <summary>Invalidate the cache (call after theme change).</summary>
     /// <remarks>
-    /// Icons are disposed immediately (form icons are reassigned right after).
-    /// Bitmap entries are NOT disposed here because ToolStripMenuItem.Image may
-    /// still reference them. The caller must reassign menu images; old bitmaps
-    /// become unreferenced and are collected by GC/finalizer.
+    /// Both icons and bitmaps are disposed immediately to prevent GDI handle leaks.
+    /// Callers must reassign any ToolStripMenuItem.Image references after this call.
     /// </remarks>
     internal static void InvalidateCache()
     {
         foreach (var icon in _cache.Values)
             icon.Dispose();
         _cache.Clear();
+        foreach (var bmp in _bmpCache.Values)
+            bmp.Dispose();
         _bmpCache.Clear();
     }
 
@@ -561,7 +561,8 @@ private static void DrawExportIcon(Graphics g, int s)
         using var pen = new Pen(Color.White, 2f) { EndCap = System.Drawing.Drawing2D.LineCap.ArrowAnchor };
         int cx = s / 2;
         g.DrawLine(pen, cx, s - 6, cx, 5);
-        g.DrawLine(new Pen(Color.White, 1.5f), s / 4, s - 5, s - s / 4, s - 5);
+        using var baseLine = new Pen(Color.White, 1.5f);
+        g.DrawLine(baseLine, s / 4, s - 5, s - s / 4, s - 5);
     }
 
     // ── Menu bitmap accessors for new icons ─────────────────────────────
@@ -931,7 +932,8 @@ private static void DrawPreferencesIcon(Graphics g, int s)
                 cy + (int)((r + 2) * Math.Sin(a2))
             );
         }
-        g.FillEllipse(new SolidBrush(AppTheme.Bg), cx - ir + 1, cy - ir + 1, (ir - 1) * 2, (ir - 1) * 2);
+        using var centerBrush = new SolidBrush(AppTheme.Bg);
+        g.FillEllipse(centerBrush, cx - ir + 1, cy - ir + 1, (ir - 1) * 2, (ir - 1) * 2);
     }
 
     /// <summary>Import icon: green downward arrow into a tray.</summary>

src/RegiLattice.GUI/Controls/RoundedPanel.cs

@@ -15,6 +15,8 @@ public sealed class RoundedPanel : Panel
     private int _borderWidth = 1;
     private float _tintAlpha = 0f; // 0 = solid BackColor, >0 = tinted
     private Color _tintColor = Color.White;
+    private Region? _cachedRegion;
+    private Size _lastRegionSize;
 
     // ── Properties ─────────────────────────────────────────────────────────
     /// <summary>Corner radius in pixels (default 10).</summary>
@@ -121,14 +123,27 @@ protected override void OnPaint(PaintEventArgs e)
             g.DrawPath(pen, path);
         }
 
-        // Clip child controls to rounded region — dispose old Region to prevent GDI leak
+        // Clip child controls to rounded region — only recreate when size changes.
+        if (_cachedRegion is null || _lastRegionSize != Size)
+        {
+            _cachedRegion?.Dispose();
+            _cachedRegion = new Region(path);
+            _lastRegionSize = Size;
+        }
         var oldRegion = Region;
-        Region = new Region(path);
+        Region = _cachedRegion.Clone();
         oldRegion?.Dispose();
 
         base.OnPaint(e);
     }
 
+    protected override void Dispose(bool disposing)
+    {
+        if (disposing)
+            _cachedRegion?.Dispose();
+        base.Dispose(disposing);
+    }
+
     // ── Helper ─────────────────────────────────────────────────────────────
     private static GraphicsPath RoundedPath(Rectangle r, int radius)
     {

src/RegiLattice.GUI/Controls/TweakBrowserPanel.cs

@@ -345,6 +345,16 @@ private async void OnToggleRequested(TweakDef td, bool enable)
     }
 
     private void OnInfoRequested(TweakDef td) => TweakInfoRequested?.Invoke(td);
+
+    protected override void Dispose(bool disposing)
+    {
+        if (disposing)
+        {
+            _debounce.Stop();
+            _debounce.Dispose();
+        }
+        base.Dispose(disposing);
+    }
 }
 
 /// <summary>

src/RegiLattice.GUI/Forms/BasePackageManagerDialog.cs

@@ -96,7 +96,11 @@ protected BasePackageManagerDialog()
             if (_prereqMet)
                 await RefreshAsync();
         };
-        FormClosed += (_, _) => _cts.Cancel();
+        FormClosed += (_, _) =>
+        {
+            _cts.Cancel();
+            _cts.Dispose();
+        };
     }
 
     // ── Layout ────────────────────────────────────────────────────────────

src/RegiLattice.GUI/Forms/MainForm.Designer.cs

@@ -237,6 +237,11 @@ protected override void OnFormClosing(FormClosingEventArgs e)
 
         _trayIcon.Visible = false;
         _cts.Cancel();
+
+        // Unsubscribe control events to break reference cycles before disposal.
+        _sidebar.ItemSelected -= OnSidebarNavSelected;
+        _treeView.NodeMouseHover -= OnTreeNodeScoreHover;
+
         base.OnFormClosing(e);
     }
 

src/RegiLattice.GUI/Forms/MainForm.cs

@@ -171,6 +171,33 @@ private static void AppendHandleStats(System.Text.StringBuilder sb)
             sb.AppendLine("(handle/memory stats unavailable)");
         }
 
+        // GC generation counts and memory pressure
+        try
+        {
+            sb.AppendLine($"GC Gen0 colls: {GC.CollectionCount(0):N0}");
+            sb.AppendLine($"GC Gen1 colls: {GC.CollectionCount(1):N0}");
+            sb.AppendLine($"GC Gen2 colls: {GC.CollectionCount(2):N0}");
+            var gcInfo = GC.GetGCMemoryInfo();
+            sb.AppendLine($"GC HeapSize  : {gcInfo.HeapSizeBytes / (1024 * 1024):N0} MB");
+            sb.AppendLine($"GC Finalize Q: {gcInfo.FinalizationPendingCount:N0} pending");
+        }
+        catch
+        {
+            sb.AppendLine("(GC details unavailable)");
+        }
+
+        // Thread pool stats — helps diagnose deadlocks and thread exhaustion
+        try
+        {
+            ThreadPool.GetAvailableThreads(out int workerAvail, out int ioAvail);
+            ThreadPool.GetMaxThreads(out int workerMax, out int ioMax);
+            sb.AppendLine($"ThreadPool   : workers {workerMax - workerAvail}/{workerMax}, IO {ioMax - ioAvail}/{ioMax}");
+        }
+        catch
+        {
+            sb.AppendLine("(thread pool stats unavailable)");
+        }
+
         // Open forms and total control count — helps identify control/handle leaks
         try
         {
@@ -185,6 +212,22 @@ private static void AppendHandleStats(System.Text.StringBuilder sb)
         {
             sb.AppendLine("(form/control stats unavailable)");
         }
+
+        // Loaded assemblies — helps diagnose version conflicts and plugin issues
+        try
+        {
+            var assemblies = AppDomain.CurrentDomain.GetAssemblies();
+            sb.AppendLine($"Loaded asms  : {assemblies.Length}");
+            foreach (var asm in assemblies)
+            {
+                var name = asm.GetName();
+                sb.AppendLine($"  {name.Name} {name.Version}");
+            }
+        }
+        catch
+        {
+            sb.AppendLine("(assembly list unavailable)");
+        }
     }
 
     private static int CountControls(Control c)

src/RegiLattice.GUI/Program.cs

@@ -99,18 +99,16 @@ public void InvalidateCache_ThenMenuBitmaps_AreValidAndFresh()
     }
 
     [Fact]
-    public void InvalidateCache_OldBitmaps_StillAccessible()
+    public void InvalidateCache_OldBitmaps_AreDisposed()
     {
         // Capture a reference to the old bitmap (like a ToolStripMenuItem.Image would)
         var oldBmp = AppIcons.PipMenuBitmap;
 
         AppIcons.InvalidateCache();
 
-        // The old bitmap must NOT be disposed — FrameDimensionsList access must not throw.
-        // This is the exact operation that crashed before the fix.
-        var dims = oldBmp.FrameDimensionsList;
-        Assert.NotNull(dims);
-        Assert.NotEmpty(dims);
+        // Old bitmaps are now properly disposed to prevent GDI handle leaks.
+        // Callers must reassign menu images after InvalidateCache().
+        Assert.Throws<ArgumentException>(() => _ = oldBmp.FrameDimensionsList);
     }
 
     [Fact]