fix: show preset parameters when they have diagnostics (#18258)

Always show preset parameters in CreateWorkspacePageViewExperimental if
the preset parameter has any diagnostics, regardless of the
showPresetParameters toggle state.

This ensures that users can see and address errors in preset parameters
even when the "Show preset parameters" toggle is disabled.

Fixes coder/internal#651

---------

Co-authored-by: blink-so[bot] <211532188+blink-so[bot]@users.noreply.github.com>
Co-authored-by: Jaayden Halko <jaayden@coder.com>

site/src/pages/CreateWorkspacePage/CreateWorkspacePageViewExperimental.tsx

@@ -620,8 +620,12 @@ export const CreateWorkspacePageViewExperimental: FC<
 										creatingWorkspace ||
 										isPresetParameter;
 
-									// Hide preset parameters if showPresetParameters is false
-									if (!showPresetParameters && isPresetParameter) {
+									// Always show preset parameters if they have any diagnostics
+									if (
+										!showPresetParameters &&
+										isPresetParameter &&
+										parameter.diagnostics.length === 0
+									) {
 										return null;
 									}