polish(admin-deploys): 2026 timeline hero + step pills + status cards

polish(admin-deploys): 2026 timeline hero + step pills + status cards

Picked up from parallel polish agent's worktree.

/admin/deploys rebuilt with:
- Hero gradient hairline + radial orb + eyebrow 'Deploys · live timeline'
- Display headline with gradient text reflecting latest state
  (green / failed / rolling out)
- Summary stats row in tabular-nums: latest SHA pill, elapsed,
  total today, success rate this week
- Each deploy row as a polished card with step pills along the
  row (git-pull / bun-install / db-migrate / build / restart /
  healthz / full-smoke) coloured by status with the duration
  in ms inline. Total duration on the right.
- Failed-deploy rows get a red gradient hairline + reason inline
- 'Trigger deploy' + 'Rollback to previous' buttons in hero
- Empty state: dashed card with orb + 'push to main to fire first'
- Live-update banner when latest deploy is in-flight

formatStepDuration() helper added for the inline pill format
('420ms', '3.4s', '1m02'). All other data fetches / queries / POST
targets preserved exactly.