This PR addresses #25556 by restoring a missing helper used by Show-Command to import modules and refresh command metadata (used by the UI when showing command details), and by preventing Show-Command from running in restricted sessions where it isn’t supported.

Changes:

• Reintroduces GetImportModuleCommand script generation logic in ShowCommandHelper to support module import + command refresh (including remote-runspace scenarios).
• Adds a restricted-session guard in ShowCommand BeginProcessing to terminate early with a clear error.
• Adds a new localized resource string for the restricted-session error message.

Suppressed comments (2)

src/Microsoft.Management.UI.Internal/commandHelpers/ShowCommandHelper.cs:511

• In the remote runspace fallback path, the serialized command script is concatenated directly after Import-Module ... without a statement separator, producing an invalid PowerShell script (e.g., Import-Module 'X'@( ... )). Add a ; before the serialized script so it runs as a separate statement.

                    scriptBase += GetSerializedCommandScript();

src/Microsoft.Management.UI.Internal/commandHelpers/ShowCommandHelper.cs:498

• isFirstChance is documented as indicating the second attempt, but the name (and default value) indicate the first attempt. This mismatch can easily lead to incorrect future call sites or changes.

        /// <param name="isRemoteRunspace">Boolean flag determining whether Show-Command is queried in the local or remote runspace scenario.</param>
        /// <param name="isFirstChance">Boolean flag to indicate that it is the second attempt to query Show-Command data.</param>
        /// <returns>The command to be run to in order to import a module and refresh the command data.</returns>

• Files reviewed: 3/3 changed files
• Comments generated: 2
• Review effort level: Lite