Fix NOTES section formatting in comment-based help (PowerShell#26512)

Author: yotsuda

src/System.Management.Automation/FormatAndOutput/DefaultFormatters/Help_format_ps1xml.cs

@@ -680,10 +680,7 @@ private static IEnumerable<FormatViewDefinition> ViewsOf_MamlCommandHelpInfo_Ful
                         .StartFrame(leftIndent: 4)
                             .AddPropertyExpressionBinding(@"title")
                             .AddNewline()
-                            .AddNewline()
-                            .StartFrame(leftIndent: 4)
-                                .AddPropertyExpressionBinding(@"alert", enumerateCollection: true, customControl: sharedControls[11])
-                            .EndFrame()
+                            .AddPropertyExpressionBinding(@"alert", enumerateCollection: true, customControl: sharedControls[11])
                             .AddNewline()
                         .EndFrame()
                     .EndEntry()

test/powershell/Language/Scripting/ScriptHelp.NotesFormatting.Tests.ps1

@@ -0,0 +1,27 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+Describe 'Comment-based help NOTES section formatting' -Tags "CI", "Feature" {
+    It 'NOTES section should have single blank line after header and 4-space indentation' {
+        $helpText = Get-Help Remove-PSSession -Full | Out-String
+        $lines = $helpText -split "`r?`n"
+
+        # Find NOTES section
+        $notesIndex = -1
+        for ($i = 0; $i -lt $lines.Count; $i++) {
+            if ($lines[$i] -match '^NOTES\s*$') {
+                $notesIndex = $i
+                break
+            }
+        }
+
+        $notesIndex | Should -BeGreaterThan -1 -Because "NOTES section should exist"
+
+        # The line after NOTES header should be blank
+        $lines[$notesIndex + 1] | Should -Match '^\s*$' -Because "There should be a blank line after NOTES header"
+
+        # The second line after NOTES header should have content with 4-space indentation
+        $contentLine = $lines[$notesIndex + 2]
+        $contentLine | Should -Match '^[ ]{4}\S' -Because "Content should have exactly 4-space indentation"
+    }
+}