Add --show-reads Support to .NET PreviewOptions and UpOptions (#542)

## Overview

This PR adds support for the `--show-reads` flag in Pulumi CLI to the
.NET SDK by introducing a new `bool? ShowReads` property in both
`PreviewOptions` and `UpOptions`.

## Changes

- Added `ShowReads` property to `PreviewOptions` and `UpOptions`.
- Passed `ShowReads` as a nullable boolean to the `pulumi preview` and
`pulumi up` CLI commands.

## Related Issue

Closes #541

---------

Co-authored-by: Hossein Margani <[email protected]>
Co-authored-by: Fraser Waters <[email protected]>
Co-authored-by: Fraser Waters <[email protected]>

Author: 3 people

.changes/unreleased/Improvements-542.yaml

@@ -0,0 +1,6 @@
+component: sdk/auto
+kind: Improvements
+body: Add --show-reads Support for Pulumi Up & Preview
+time: 2025-03-13T11:33:14.4527021Z
+custom:
+    PR: "542"

sdk/Pulumi.Automation/PreviewOptions.cs

@@ -35,5 +35,10 @@ public sealed class PreviewOptions : UpdateOptions
         /// Refresh the state of the stack's resources before this preview.
         /// </summary>
         public bool? Refresh { get; set; }
+
+        /// <summary>
+        /// Show resources that are being read in, alongside those being managed directly in the stack.
+        /// </summary>
+        public bool? ShowReads { get; set; }
     }
 }

sdk/Pulumi.Automation/Pulumi.Automation.xml

@@ -45,5 +45,10 @@ public sealed class UpOptions : UpdateOptions
         /// Refresh the state of the stack's resources before this update.
         /// </summary>
         public bool? Refresh { get; set; }
+
+        /// <summary>
+        /// Show resources that are being read in, alongside those being managed directly in the stack.
+        /// </summary>
+        public bool? ShowReads { get; set; }
     }
 }

sdk/Pulumi.Automation/UpOptions.cs

@@ -332,6 +332,12 @@ public async Task<UpResult> UpAsync(
                 if (options.ExpectNoChanges is true)
                     args.Add("--expect-no-changes");
 
+                if (options.ShowReads.HasValue)
+                {
+                    var showReads = options.ShowReads.Value ? "true" : "false";
+                    args.Add($"--show-reads={showReads}");
+                }
+
                 if (options.Diff is true)
                     args.Add("--diff");
 
@@ -447,6 +453,12 @@ public async Task<PreviewResult> PreviewAsync(
                 if (options.ExpectNoChanges is true)
                     args.Add("--expect-no-changes");
 
+                if (options.ShowReads.HasValue)
+                {
+                    var showReads = options.ShowReads.Value ? "true" : "false";
+                    args.Add($"--show-reads={showReads}");
+                }
+
                 if (options.Diff is true)
                     args.Add("--diff");