Following up on #49183 which fixed the category filter for remote extensions. This PR applies the same category filter logic to **dev extensions**. Previously, dev extensions were always shown regardless of the selected category filter (e.g., "Themes", "Languages"). Changes: - Add `filtered_dev_extension_indices` to track which dev extensions match the active `provides_filter` - Add `dev_extension_matches_provides()` helper to map `ExtensionManifest` fields to `ExtensionProvides` variants - Update `render_extensions()` and list count to use filtered dev extension indices Release Notes: - Fixed extension category filter not applying to dev extensions in the extensions panel. --------- Co-authored-by: Claude <noreply@anthropic.com> Co-authored-by: Marshall Bowers <git@maxdeviant.com>