New /components route showing every ui primitive (Panel, StatusChip,
Table) in each mode it supports: Panel with/without a title,
StatusChip's four tones, Table populated and empty. Sample data only,
no API calls, so it renders identically regardless of backend state.
Linked from the Shell nav next to "overview".
Verified with npm run build + npm run typecheck, and a headless
chromium screenshot of the built dist.