themes_thumbnail@2x.png 404 in editor theme thumbnails

[moodyjmz]

TL;DR: Editors request sdkjs/common/Images/themes_thumbnail@2x.png, which 404s. Surfaced during the Euro-Office/web-apps webpack migration (#109), but the asset lives here in sdkjs.

Detail

• Path: common/Images/themes_thumbnail@2x.png, referenced from editor theme-thumbnail rendering.
• Returns 404 — the @2x asset appears to be missing from the deployed sdkjs Images.
• Out of scope for web-apps (asset is sdkjs-side); filing here as the correct home. Noticed during build: replace Grunt+r.js with webpack 5 — Phase E complete web-apps#109.