Add daily version suffix for extension CI builds

Mirrors core CLI pattern: appends -daily.<BuildId> for CI builds,
-pr.<BuildId> for PR builds, skips for Manual (release) builds.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: rajeshkamal5050

eng/pipelines/templates/stages/build-and-test-azd-extension.yml

@@ -110,6 +110,10 @@ stages:
         steps:
           - checkout: self
 
+          - template: /eng/pipelines/templates/steps/set-extension-version-cd.yml
+            parameters:
+              AzdExtensionDirectory: ${{ parameters.AzdExtensionDirectory }}
+
           - task: PowerShell@2
             displayName: Set extension version variable
             inputs:

eng/pipelines/templates/steps/set-extension-version-cd.yml

@@ -0,0 +1,15 @@
+parameters:
+  - name: AzdExtensionDirectory
+    type: string
+
+steps:
+  - task: PowerShell@2
+    displayName: Set extension version for CD release
+    inputs:
+      pwsh: true
+      targetType: filePath
+      filePath: eng/scripts/Set-ExtensionVersionInBuild.ps1
+      arguments: >-
+                -ExtensionDirectory ${{ parameters.AzdExtensionDirectory }}
+                -BuildReason ($env:BUILDREASONOVERRIDE ?? '$(Build.Reason)')
+                -BuildId $(Build.BuildId)

eng/scripts/Set-ExtensionVersionInBuild.ps1

@@ -0,0 +1,41 @@
+<#
+    .SYNOPSIS
+    Appends a prerelease suffix to the extension's version.txt for CI/PR builds.
+    Skips for Manual (release) builds.
+
+    .PARAMETER ExtensionDirectory
+    Path to the extension directory containing version.txt.
+
+    .PARAMETER BuildReason
+    The build reason from CI (e.g. Build.Reason).
+
+    .PARAMETER BuildId
+    A unique build ID from CI (e.g. Build.BuildId).
+ #>
+param(
+    [Parameter(Mandatory)] [string] $ExtensionDirectory,
+    [string] $BuildReason,
+    [string] $BuildId
+)
+
+Write-Host "Build reason: $BuildReason"
+
+$prereleaseCategory = ""
+
+if ($BuildReason -eq "Manual") {
+    Write-Host "Skipping prerelease tagging for release build."
+    exit 0
+}
+elseif ($BuildReason -eq "PullRequest") {
+    $prereleaseCategory = "pr"
+}
+else {
+    $prereleaseCategory = "daily"
+}
+
+$versionFile = Join-Path $ExtensionDirectory "version.txt"
+$version = Get-Content $versionFile
+$newVersion = "$version-$prereleaseCategory.$BuildId"
+
+Set-Content $versionFile -Value $newVersion
+Write-Host "Set version.txt contents to: $newVersion"