v0.4.0 — Rich Editor & Mobile Polish

- Web Bookmarks & Embeds: Paste a URL to get a rich link preview card, or embed external content with iframe support and screenshot fallbacks inside editor - Editor Block Movement: alt + up/down to reorder blocks; shift + cmd + v for plain-text paste - Link Bubble Menu: Hover over links to preview, edit, or remove them without leaving the editor - Text & Highlight Colors: Color pickers in the formatting toolbar for text and background highlights - Mobile Formatting Toolbar: Optimized toolbar for mobile editing - Draft Preview Links: Share preview links for unpublished drafts - Toast Notifications: Global feedback system for actions across the app