assets: GitHub social preview card

[frahlg]

Part of #106.

Adds assets/social-preview.png (1280×640) — the card GitHub shows when the
repo link is pasted into Slack, X, or LinkedIn — and the HTML it renders from,
so it can be regenerated.

Fredrik: one manual step

This cannot be set from the CLI. Upload the PNG at:

GitHub → the repo → Settings → General → Social preview → Edit → Upload an image

Pick assets/social-preview.png from a checkout of this branch (or download it
from the Files tab of this PR).

What is on the card

Everything is README.md's hero, unchanged:

• MIRANDA, small and letterspaced, top left
• Leave your desk. Keep your terminal. — the headline, 106px
• The reach layer for persistent terminals. — one supporting line
• 12 ms on a LAN · end-to-end encrypted · no VPN, no SSH keys

The 12 ms is the lan-direct p50 in netsim/results/results.md. No claim on
the card that README.md does not already make.

Design

Dark ground #0D1117, a lower plane in #151B23, paper-white text, one accent
in signal orange #FF7A45. Familjen Grotesk 700 for the headline, IBM Plex Mono
500 for the wordmark and the proof row.

The only visual device is the card's own structure: two stacked planes, with the
accent sitting on the seam between them — the direct path, at the layer Miranda
is. Nothing else is drawn.

It is built to survive being a thumbnail. At 400px wide the headline and the
supporting line both still read.

Regenerating

The command is in a comment at the top of assets/social-preview.html, the way
assets/demo.tape documents the GIF:

"/Applications/Google Chrome.app/Contents/MacOS/Google Chrome" \
  --headless --disable-gpu --hide-scrollbars \
  --force-device-scale-factor=1 --window-size=1280,640 \
  --virtual-time-budget=4000 \
  --screenshot=assets/social-preview.png \
  "file://$PWD/assets/social-preview.html"

The three webfonts are embedded as base64 (latin subsets, OFL 1.1), so the
render never touches the network and never quietly falls back to a system face.
Re-running the command reproduces the PNG byte for byte.

Checks

• sips -g pixelWidth -g pixelHeight → 1280 × 640
• cd go && go test ./... passes
• cd web && npm test passes, 167/167
• No new dependencies. Nothing outside assets/ changed.

🤖 Generated with Claude Code

https://claude.ai/code/session_01KeiotDVE94wEzvc7wcvm1y

---

Note

Low Risk
Marketing assets only under assets/; no application, auth, or runtime behavior changes.

Overview
Adds a 1280×640 GitHub social preview for link unfurls (Slack, X, etc.): assets/social-preview.html as the source layout and the companion assets/social-preview.png to upload under repo Settings → Social preview.

The card reuses the README hero (wordmark, headline, tagline, proof row with 12 ms on a LAN from netsim results). Styling is self-contained—dark palette, two-plane layout with an accent seam—and Familjen Grotesk / IBM Plex Mono are embedded as base64 so headless Chrome screenshots do not depend on network fonts.

Regeneration is documented in the HTML header (Chrome headless screenshot + sips dimension check), similar to how assets/demo.tape documents the demo GIF.

^{Reviewed by Cursor Bugbot for commit 7962d97. Bugbot is set up for automated code reviews on this repo. Configure here.}

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Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-08-30T14:00:16.244494Z	7962d97	PR opened

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