Per mara: the agent sub-pages should use the same back-link nav as the
dashboard's standalone pages, while the live terminal page stays as-is (no
tabs of each other, not an SPA).
Pull the shared `@hive/shared/chrome.css` into the agent bundle (via agent.css's
existing @import line; esbuild inlines it into the one dist/static/agent.css all
agent pages link), then:
- stats.html: replace the ASCII banner + bespoke `.stats-nav` with the shared
`page-header` (← live back-link + dashboard link + title). Keeps the #back-link
/ #dashboard-link / #title ids stats.js drives, and the time-window picker +
charts below are unchanged.
- screen.html: replace the bespoke `#toolbar` nav with the same `page-header`
(← agent back-link + title), keeping the fit / match / debug controls + the
status text in the bar.
The live terminal (index.html) is untouched. The now-unused `.banner` /
`.stats-nav` / `#toolbar` rules in agent.css are left for a follow-up prune to
keep this diff focused on the markup. Agent build clean.
Closes#1874.
98d015edea