Understudy Desktop v0.3.39

What's Changed

• De-experimentalize the desktop → production train-api connection by @lluisinthedesert in #306
• feat(desktop): management consolidation — Aamir's control-plane surfaces + nav into the app by @lluisinthedesert in #308
• feat(desktop): management consolidation — control-plane surfaces + nav (ACTUAL migration) by @lluisinthedesert in #309
• release: Desktop 0.3.39 / CLI 0.6.36 by @lluisinthedesert in #310

Full Changelog: desktop-v0.3.38-mvp...desktop-v0.3.39-mvp