Canva

Build me a small canvas design editor to replace Canva Pro. Requirements: - A local web app: Fabric.js on a canvas element with vanilla JS, and a tiny Express server for saving and export. Script tags only, no build step. - Canvas presets: Instagram post 1080x1080, story 1080x1920, X header 1500x500, A4 poster, plus a custom-size dialog. - Editing: text using my local fonts, image upload, rectangles and lines, a layer list with reorder, align-to-center helpers, and snap guides at the canvas center. - A brand panel loaded from brand.json: my 4 colors and 2 fonts as one-click swatches. - Every design serializes to designs/<name>.json and reopens exactly; duplicate-as-template is the template system. Ship 3 starter designs. - Export PNG at 1x and 2x via Fabric's toDataURL, and PDF by printing the canvas page with Playwright. - All files local, no accounts, no telemetry. - Out of scope: stock photos, AI image tools, and collaboration. The asset library is what the Pro fee buys, I bring my own images. - README: how to add fonts and where designs live on disk.