Fix template list becoming unclickable with many entries via Dock layout

lstTemplates was a direct child of tabTemplates with an explicit pixel
Size, computed once against this dev machine's tab-strip height under
its own DPI/font scale. On the operator's real machine, adding enough
templates pushed rows past the control's actual bottom edge -
maximizing the window didn't help, confirming it wasn't a screen-space
problem but a stale size assumption baked into the designer file (the
same root cause as the earlier add/remove-button visibility bug).

Moved the button strip + list into their own panel (pnlTemplateList),
with the buttons Dock=Top and lstTemplates Dock=Fill - the list's
bounds are now computed by the layout engine against the real
container at runtime, with no absolute size to be wrong about,
regardless of DPI/font scale/window size.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

outlook-bulk-sender/BulkArchiveMailer.AddIn/UI/SettingsForm.Designer.cs

@@ -35,6 +35,8 @@ namespace BulkArchiveMailer.AddIn.UI
         private System.Windows.Forms.Label lblFromAccount;
         private System.Windows.Forms.ComboBox cboFromAccount;
 
+        private System.Windows.Forms.Panel pnlTemplateList;
+        private System.Windows.Forms.Panel pnlTemplateButtons;
         private System.Windows.Forms.ListBox lstTemplates;
         private System.Windows.Forms.Button btnAddTemplate;
         private System.Windows.Forms.Button btnRemoveTemplate;
@@ -80,6 +82,8 @@ namespace BulkArchiveMailer.AddIn.UI
             this.lblFromAccount = new System.Windows.Forms.Label();
             this.cboFromAccount = new System.Windows.Forms.ComboBox();
 
+            this.pnlTemplateList = new System.Windows.Forms.Panel();
+            this.pnlTemplateButtons = new System.Windows.Forms.Panel();
             this.lstTemplates = new System.Windows.Forms.ListBox();
             this.btnAddTemplate = new System.Windows.Forms.Button();
             this.btnRemoveTemplate = new System.Windows.Forms.Button();
@@ -105,6 +109,8 @@ namespace BulkArchiveMailer.AddIn.UI
             this.tabControl.SuspendLayout();
             this.tabGeneral.SuspendLayout();
             this.tabTemplates.SuspendLayout();
+            this.pnlTemplateList.SuspendLayout();
+            this.pnlTemplateButtons.SuspendLayout();
             this.SuspendLayout();
 
             //
@@ -213,9 +219,7 @@ namespace BulkArchiveMailer.AddIn.UI
             this.tabTemplates.Text = "Шаблоны";
             this.tabTemplates.Padding = new System.Windows.Forms.Padding(12);
             this.tabTemplates.UseVisualStyleBackColor = true;
-            this.tabTemplates.Controls.Add(this.btnAddTemplate);
-            this.tabTemplates.Controls.Add(this.btnRemoveTemplate);
-            this.tabTemplates.Controls.Add(this.lstTemplates);
+            this.tabTemplates.Controls.Add(this.pnlTemplateList);
             this.tabTemplates.Controls.Add(this.lblTplDisplayName);
             this.tabTemplates.Controls.Add(this.txtTplDisplayName);
             this.tabTemplates.Controls.Add(this.lblTplFileSuffix);
@@ -230,50 +234,74 @@ namespace BulkArchiveMailer.AddIn.UI
             this.tabTemplates.Controls.Add(this.txtTplBody);
             this.tabTemplates.Controls.Add(this.lblTplHint);
 
-            // btnAddTemplate / btnRemoveTemplate
+            // pnlTemplateList
             //
-            // Deliberately placed ABOVE lstTemplates (not below it) so
-            // their visibility never depends on how much vertical room is
-            // left over at the bottom of the tab page after the list -
-            // that computation (tab-strip height under the operator's
-            // actual DPI/font scale, which this code cannot know at design
-            // time) is exactly what went wrong before: lstTemplates ran all
-            // the way to the tab page's real bottom edge with only ~6px to
-            // spare for the buttons beneath it, which was enough on some
-            // machines and not on others. Anchored Top|Left (fixed
-            // distance from the tab page's top-left corner) rather than
-            // Bottom, they are visible as long as the tab page itself is
-            // visible at all - not merely as long as it is "tall enough".
-            this.btnAddTemplate.Location = new System.Drawing.Point(15, 20);
+            // Left-column container for the template picker (buttons +
+            // list). Its own outer Location/Size/Anchor still use fixed
+            // pixel coordinates relative to the tab page, exactly like
+            // before - that outer placement was never the problem. What
+            // is Dock-based from here down is everything INSIDE this
+            // panel, which is the part that actually broke on a real
+            // machine: lstTemplates used to be a direct child of
+            // tabTemplates with an explicit Size, so its bottom edge (and
+            // therefore its scrollability/clickability once many
+            // templates were added) depended on a hand-computed pixel
+            // height that was only ever verified on the dev machine's own
+            // DPI/font scale. Docking removes that computation entirely -
+            // see pnlTemplateButtons/lstTemplates below.
+            this.pnlTemplateList.Location = new System.Drawing.Point(15, 20);
+            this.pnlTemplateList.Size = new System.Drawing.Size(190, 467);
+            this.pnlTemplateList.Anchor = ((System.Windows.Forms.AnchorStyles)(((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom)
+                        | System.Windows.Forms.AnchorStyles.Left)));
+            // Dock order matters here: pnlTemplateButtons (Dock=Top) is
+            // added FIRST, lstTemplates (Dock=Fill) SECOND, so the Fill
+            // control's layout is computed against whatever client area
+            // remains under the already-docked top strip.
+            this.pnlTemplateList.Controls.Add(this.pnlTemplateButtons);
+            this.pnlTemplateList.Controls.Add(this.lstTemplates);
+
+            // pnlTemplateButtons
+            //
+            // Fixed-height strip pinned to the top of pnlTemplateList.
+            // btnAddTemplate/btnRemoveTemplate live inside it at a fixed
+            // offset from ITS top-left corner (0,0)/(95,0) - a small,
+            // never-resized container, so plain Location placement here
+            // carries none of the earlier risk (that risk only existed
+            // when the same fixed coordinates were relative to the whole,
+            // variable-height tab page).
+            this.pnlTemplateButtons.Dock = System.Windows.Forms.DockStyle.Top;
+            this.pnlTemplateButtons.Size = new System.Drawing.Size(190, 35);
+            this.pnlTemplateButtons.Controls.Add(this.btnAddTemplate);
+            this.pnlTemplateButtons.Controls.Add(this.btnRemoveTemplate);
+
+            // btnAddTemplate
+            this.btnAddTemplate.Location = new System.Drawing.Point(0, 0);
             this.btnAddTemplate.Size = new System.Drawing.Size(90, 27);
             this.btnAddTemplate.Text = "+ Добавить";
             this.btnAddTemplate.UseVisualStyleBackColor = true;
-            this.btnAddTemplate.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Left)));
             this.btnAddTemplate.Click += new System.EventHandler(this.btnAddTemplate_Click);
 
             // btnRemoveTemplate
-            this.btnRemoveTemplate.Location = new System.Drawing.Point(115, 20);
+            this.btnRemoveTemplate.Location = new System.Drawing.Point(95, 0);
             this.btnRemoveTemplate.Size = new System.Drawing.Size(90, 27);
             this.btnRemoveTemplate.Text = "Удалить";
             this.btnRemoveTemplate.UseVisualStyleBackColor = true;
-            this.btnRemoveTemplate.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Left)));
             this.btnRemoveTemplate.Click += new System.EventHandler(this.btnRemoveTemplate_Click);
 
             // lstTemplates
             //
-            // Starts below the two buttons now (y=55, was y=20) and still
-            // stretches down to the bottom of the tab page (Anchor
-            // Top|Bottom|Left) - only its OWN bottom edge is at risk of
-            // being visually tight against the tab page's real bottom
-            // edge if the assumed content height is off, which just means
-            // slightly less of the list is visible at once (it already has
-            // a scrollbar - IntegralHeight = false - so this degrades
-            // gracefully) rather than an entire control disappearing.
-            this.lstTemplates.Location = new System.Drawing.Point(15, 55);
-            this.lstTemplates.Size = new System.Drawing.Size(190, 432);
+            // Dock=Fill: always occupies exactly whatever area of
+            // pnlTemplateList is left below pnlTemplateButtons, computed
+            // by the layout engine at every resize/DPI - not a hand-picked
+            // pixel height that can end up too short (and therefore
+            // effectively unscrollable/unclickable for items past the cut
+            // -off) on a machine with different DPI/font scaling than the
+            // one this was last tested on. IntegralHeight = false just
+            // means the list doesn't force its height to a whole multiple
+            // of the item height - irrelevant to whether Fill can "escape"
+            // the panel, which it structurally cannot.
+            this.lstTemplates.Dock = System.Windows.Forms.DockStyle.Fill;
             this.lstTemplates.IntegralHeight = false;
-            this.lstTemplates.Anchor = ((System.Windows.Forms.AnchorStyles)(((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom)
-                        | System.Windows.Forms.AnchorStyles.Left)));
             this.lstTemplates.SelectedIndexChanged += new System.EventHandler(this.lstTemplates_SelectedIndexChanged);
 
             // lblTplDisplayName
@@ -399,6 +427,8 @@ namespace BulkArchiveMailer.AddIn.UI
             this.tabControl.ResumeLayout(false);
             this.tabGeneral.ResumeLayout(false);
             this.tabGeneral.PerformLayout();
+            this.pnlTemplateButtons.ResumeLayout(false);
+            this.pnlTemplateList.ResumeLayout(false);
             this.tabTemplates.ResumeLayout(false);
             this.tabTemplates.PerformLayout();
             this.ResumeLayout(false);