chore(site): add devin icon - #28206

Summary

Adds a Devin icon (site/static/icon/devin.svg) for Cognition's Devin product family (Devin Desktop, the June 2, 2026 rebrand of Windsurf, plus Devin Cloud/CLI/Review). No module wiring yet, that follows once coder/registry#1050 (new devin-desktop module) is merged and released, and coderd/templatebuilder's module catalog is regenerated against it.

Changes

• site/static/icon/devin.svg: 256x256 viewBox, single white path, matching this directory's existing icon convention (e.g. windsurf.svg, zed.svg). Source: adapted from the MIT-licensed @lobehub/icons-static-svg package (icons/devin.svg), mathematically rescaled from its native 24x24 viewBox to 256x256 and recolored to white. Same source used for the matching icon in feat: add devin-desktop module registry#1050.
• site/src/theme/icons.json: regenerated via make site/src/theme/icons.json to include the new file.
• site/src/theme/externalImages.ts: added ["/icon/devin.svg", "monochrome"], same treatment as windsurf.svg.

Naming

Named devin.svg, not devin-desktop.svg, matching how this registry/site already name icons after the umbrella brand rather than the specific product surface (e.g. claude-code module uses claude.svg, vscode-desktop/vscode-web/code-server all use code.svg). Cognition ships several Devin-branded surfaces (Desktop, Cloud, CLI, Review) that would reasonably share this mark.

Validation

• pnpm exec biome check --error-on-warnings on the two changed TS/JSON files: clean.
• pnpm exec vitest run src/theme/externalImages.test.ts src/utils/externalImageSources.test.ts: 24/24 pass.
• make pre-commit: passes, including lint/site-icons.

🤖 This PR was created with the help of Coder Agents, and needs a human review. 🧑💻