feat(dashboard): add stats panel and refresh layout

[thomascolden585-svg]

Summary

Closes #93

• Adds a StatsPanel KPI strip above the main dashboard grid for a quick at-a-glance view of network activity.
• Refreshes the hero section: eyebrow + h1 title + supporting copy, with a "Live" indicator (pulsing dot) grouped next to BlockIndicator in a single status chip.
• Introduces a shared panelSx style for all dashboard panels (MinerRatesTable, OrderbookDepth, ReservationsTracker, EventFeed, SwapTracker) so spacing/border/background stay consistent and a small accent bar marks each panel.
• Mode-aware accents: dark mode uses indigo + emerald with a soft glow on the live dot; light mode keeps the existing royal-blue / neon-green palette.
• Tightens responsive spacing (xs/sm/md) around the hero, KPI strip, and grid.

Files changed

• src/pages/DashboardPage.tsx — layout refresh, new StatsPanel slot, shared panelSx, live indicator.

Test plan

• npm run build succeeds with no type errors.
• npm run lint passes.
• npm run dev — load /dashboard and verify:
  • Hero renders with eyebrow ("Network Activity / SN7"), title, and description.
  • "Live" dot pulses; BlockIndicator sits to its right in the same chip.
  • StatsPanel renders above the main grid.
  • All five panels (MinerRatesTable, OrderbookDepth, ReservationsTracker, EventFeed, SwapTracker) share the same border, background, padding, and accent bar.
  • Light mode: blue/green accents look correct.
  • Dark mode: indigo accent + emerald live dot with glow look correct.
  • Responsive: hero stacks vertically on xs; grid columns collapse correctly on xs/sm/md.
• No regressions in BlockIndicator block-height updates.

Notes

• No API or data-fetching changes; this PR is layout/visual only.
• Branch: fix/dashboard-reservations-display → test.