- add the integrations page sidebar with collapsible icon-only navigation and Figma-aligned marketplace card
- move custom integration SVGs into the iconify collection and document the Tailwind i-custom workflow
- preserve source SVG collection dimensions when flattening generated icon data so existing main nav icons keep their 20x20 viewBox
- add an icon dimension guard for layout-sensitive generated icons
- update model provider routing, i18n, and focused frontend tests