fix(ui): target submenu input and expose the resize surface

Refs #8, #9. Keep settings/table/physical-resize assertions; verify pointer identity and dismiss the depth popup before dragging.

Co-Authored-By: Codex (GPT-6) <noreply@openai.com>
Signed-off-by: James Maes <jmaes@dmdbrands.com>

docs/SESSION-STATE.md

@@ -49,13 +49,23 @@ exact failure in InstalledUpdates.Tests.ps1: CommandInfo.get_Parameters ->
 UseCorrectCasing.AnalyzeScript, matching upstream #1708. Locally verified workaround
 checks casing alone, then every other rule; all 13 files and both negative fixtures
 pass, plus a bounded 20-iteration offending-file probe. CI must verify this change;
-no suppression, retry or analyzer-version change. Recent successes alone are not a fix.
+no suppression, retry or analyzer-version change. Signed local ce9afc62378a1275dc723ee444066bd2c732cef5
+contains the workaround; push with the input follow-up after all prior producers ended.
 
 ## Outline milestone being prepared
 
 Pushed outline head: 5c3988e012b46aff2959eabd16c6de2b7381ab04. Authoritative CI
-38104585881 and CodeQL 38104585849 are live; security/pr-gates passed, scripts
-38104585530 failed with the captured race above. Do not restart or supersede live runs.
+38104585881 is terminal FAILURE: 31/33 native/UI pass, including actual heading jumps,
+independent nested collapse and retained theme/reload state. Depth choices pass; physical
+resize fails. Frontmatter still fails because Markdown click never dispatched: settings
+remain Metadata, only one reload logged, submenu remains open. CodeQL 38104585849,
+security and PR gates passed; scripts 38104585530 captured the race above.
+
+Follow-up adds an explicit Thumb hit-test template. Physical mouse helper moves directly
+to the requested control, verifies that exact target or its descendant, then clicks;
+an animated path across parent menu rows can close a submenu before the click. Depth
+popup is explicitly collapsed before real divider drag and hit identity checked.
+Settings/table/resize assertions remain; no local GUI input. Hosted verification needed.
 
 Issue #9: sanitized heading labels, GFM fragment mapping, generated numeric identities,
 stack-free section construction, duplicate/nested headings and passive markup.

docs/TODO.md

@@ -17,7 +17,8 @@
 - [x] Implement persisted editable theme overrides/custom names, color/code-font/CSS controls and built-in restoration.
 - [x] Complete hosted theme editor/validation/restoration acceptance (issue #7): CI 38102867556 passed; size 17 edit also passes in 29/30 later UI tests.
 - [x] Implement persistent resizable TOC/depth, safe heading/local-fragment jumps and independent nested section collapse (issue #9).
-- [ ] Verify hosted outline depth/resize/scroll/collapse/theme/reload acceptance.
+- [x] Verify hosted heading jumps, independent nested collapse and theme/reload state on 5c3988e (31/33 UI pass).
+- [ ] Verify physical sidebar resize and frontmatter input follow-up; keep exact assertions.
 - [ ] Add source pane, synchronized navigation, find and vim keys.
 - [x] Implement and core-test hidden/metadata/Markdown frontmatter modes, with persisted native controls and attribution.
 - [ ] Verify actual hosted frontmatter mode switching and code-font size editing.

src/MarkdownViewr.Windows/MainWindow.xaml

@@ -86,7 +86,13 @@
                <Button x:Name="ExpandSections" Content="Expand all" HorizontalAlignment="Stretch" Click="ExpandSections_Click" />
             </StackPanel>
          </Grid>
-         <primitives:Thumb x:Name="OutlineDivider" Grid.Column="1" Background="{ThemeResource DividerStrokeColorDefaultBrush}" DragDelta="OutlineDivider_DragDelta" DragCompleted="OutlineDivider_DragCompleted" AutomationProperties.Name="Resize table of contents" />
+         <primitives:Thumb x:Name="OutlineDivider" Grid.Column="1" Background="{ThemeResource DividerStrokeColorDefaultBrush}" DragDelta="OutlineDivider_DragDelta" DragCompleted="OutlineDivider_DragCompleted" AutomationProperties.Name="Resize table of contents">
+            <primitives:Thumb.Template>
+               <ControlTemplate TargetType="primitives:Thumb">
+                  <Border Background="{TemplateBinding Background}" />
+               </ControlTemplate>
+            </primitives:Thumb.Template>
+         </primitives:Thumb>
          <WebView2 x:Name="DocumentView" Grid.Column="2" Loaded="DocumentView_Loaded" AutomationProperties.Name="Markdown document" />
       </Grid>
    </Grid>

tests/MarkdownViewr.Windows.UiTests/AppSession.cs

@@ -236,13 +236,36 @@ public sealed class AppSession : IDisposable
             return hitProcess == App.ProcessId && element.IsEnabled && !element.IsOffscreen ? element : null;
          },
          $"an unobscured mouse target '{automationId}'");
-      element.Click();
+      // Move directly: an animated path across parent-menu rows can close the target submenu.
+      AssertMouseTarget(element);
+      Mouse.LeftClick();
       Wait.UntilInputIsProcessed();
       LastMouseInput += $" Mouse after={Mouse.Position}; hit PID={Automation.FromPoint(Mouse.Position).Properties.ProcessId.ValueOrDefault}.";
    }
 
 
 
+   /// <summary>Moves once to the current target and verifies the pointer is over it or one of its children.</summary>
+   private void AssertMouseTarget(AutomationElement element)
+   {
+      if(!element.TryGetClickablePoint(out System.Drawing.Point point))
+      {
+         throw new InvalidOperationException("The native mouse target no longer has a clickable point.");
+      }
+      Mouse.Position = point;
+      Wait.UntilInputIsProcessed();
+      AutomationElement? hit = Automation.FromPoint(Mouse.Position);
+      for(int depth = 0; hit is not null && depth < 8; depth++, hit = hit.Parent)
+      {
+         if(hit.Equals(element))
+         {
+            return;
+         }
+      }
+      throw new InvalidOperationException("The pointer is not over the requested native control. " + LastMouseInput);
+   }
+
+
    /// <summary>Invokes the element carrying <paramref name="automationId"/> (a button, for example).</summary>
    public void ClickElement(string automationId) => Invoke(WaitForElement(automationId));
 

tests/MarkdownViewr.Windows.UiTests/AppTests.cs

@@ -195,7 +195,7 @@ public class AppTests
       }
       catch(TimeoutException exception)
       {
-         throw new TimeoutException($"{exception.Message} Settings: {session.ReadSettings()} Logs: {session.ReadLogs()} Native tree: {session.DescribeDocumentStatus()}", exception);
+         throw new TimeoutException($"{exception.Message} Input: {session.LastInvocation} {session.LastMouseInput} Settings: {session.ReadSettings()} Logs: {session.ReadLogs()} Native tree: {session.DescribeDocumentStatus()}", exception);
       }
       session.WaitFor(() => session.FindInApp(cf => cf.ByName("Visible metadata")), "the rendered frontmatter heading");
       session.InvokeMenuItem("View", "FrontmatterMenu");
@@ -219,10 +219,12 @@ public class AppTests
       session.WaitForElementGone("OutlineHeading:1");
       session.WaitForElement("OutlineDepth").AsComboBox().Select(3);
       session.WaitForElement("OutlineHeading:2");
+      session.WaitForElement("OutlineDepth").Patterns.ExpandCollapse.Pattern.Collapse();
       AutomationElement divider = session.WaitForElement("OutlineDivider");
       session.MainWindow.SetForeground();
       Assert.True(divider.TryGetClickablePoint(out System.Drawing.Point start));
       Assert.Equal(session.App.ProcessId, session.Automation.FromPoint(start).Properties.ProcessId.ValueOrDefault);
+      Assert.Equal("OutlineDivider", session.Automation.FromPoint(start).Properties.AutomationId.ValueOrDefault);
       FlaUI.Core.Input.Mouse.DragHorizontally(start, 70);
       session.WaitFor(
          () =>