shell.css (chat sidebar · Developers dock · GPUs panel) was still on the old
charcoal palette; snap it to the canonical monochrome tokens the Home already
uses: page #000 · surface #0a0a0a · raised #1a1a1a · border #1f1f1f · text
#ededed · dim #888 · brand/CTA #fff. Semantic green (online) / red (error) kept.
The shared shell now matches the create experience + the chat's own empty-state
and friendly-error work already on main.