Make founders email selectable in feedback success view (#1733)

Add .textSelection(.enabled) to the success body text so users can
select and copy the founders@manaflow.com email address.

Co-authored-by: Lawrence Chen <lawrencecchen@users.noreply.github.com>

Sources/ContentView.swift

@@ -9393,6 +9393,7 @@ private struct SidebarFeedbackComposerSheet: View {
             )
             .font(.system(size: 12))
             .foregroundStyle(.secondary)
+            .textSelection(.enabled)
 
             HStack {
                 Spacer()