fix(storybook): ignore non-component exports in the icon catalog #2541

After #2538 added ICON_SIZE to the shared icon seam, the Lucide icon story started treating that plain object as a React component. The production Storybook build now throws React error #130 when design-system-icons--lucide-icons mounts.

I hit this while running the full Storybook smoke for an unrelated sidebar fix. The Storybook job on #2538 was skipped by the change plan, so the regression is present on current main.

Repro:

npm --workspace @maka/desktop run build-storybook
npm --workspace @maka/desktop run smoke:storybook

The catalog should keep auto-tracking icon exports, but filter the namespace to valid component-shaped values before rendering it. I can send the small story fix and verify the full smoke run before reopening the sidebar PR.