Social preview image: docs/media/og.svg/png, with Open Graph and Twitter card tags in the web app

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

ATTRIBUTION.md

@@ -15,6 +15,7 @@ is committed and listed here with its exports.
 | File | Author | Source | Licence |
 |---|---|---|---|
 | docs/media/ibeam-analysis.mp4, docs/media/ibeam-analysis.gif | FieldCraft contributors | Original: the FieldCraft window captured during an MCP session, generated by `tools/demo-video/make.py` | MIT OR Apache-2.0 |
+| docs/media/og.svg, docs/media/og.png | FieldCraft contributors | Original social-preview image (1280 × 640): the application icon's cube layer (assets/app-icon/FieldCraft.icon/Assets/02-part.svg) beside the name and tagline set in Inter (OFL, crates/ui-egui/fonts) | MIT OR Apache-2.0 |
 | docs/media/bracket-partition.png, docs/media/bracket-hex.png, docs/media/bracket-stress.png, docs/media/setup-symbols.png | FieldCraft contributors | Original: FieldCraft renders (headless MCP screenshots and a window capture) of corpus parts and the cantilever sample | MIT OR Apache-2.0 |
 | crates/decks/tests/golden/nastran/*.bdf | FieldCraft contributors | Written by our Nastran writer from our own test models (crates/decks/tests/nastran.rs) | MIT OR Apache-2.0 |
 | assets/icons/assembly.instance.svg, assets/icons/assembly.instance.vectorcraft | FieldCraft contributors | Original toolbar icon drawn with VectorCraft from `assets/icons/src/assembly.instance.json` (`cargo xtask icons`) | MIT OR Apache-2.0 |