feat(dashboard): depth-of-market orderbook + 3-column activity feeds

[e35ventura]

Summary

Reworks the dashboard into a trading-terminal layout and wires in the Depth of Market orderbook.

• Right column → Depth of Market orderbook. Surfaces cumulative miner liquidity at each rate (the existing OrderbookDepth, previously unused).
• Orderbook is driven by the shared chart direction. Its own dropdown is removed; the market-rate chart's BTC↔TAO toggle now drives the chart, the Active Rates table, and the orderbook together, so they're always in sync.
• BOTH view = two-sided book. The chart's BOTH state is lifted to the page; in BOTH the orderbook overlays both sides on one shared TAO/BTC price axis — asks (TAO→BTC) above, bids (BTC→TAO) below — with a Spread divider showing the gap, like a traditional depth-of-market book.
• Chart line colors match the orderbook. BTC→TAO uses the BTC accent, TAO→BTC uses the TAO accent (both theme tokens), so chart and book are color-consistent.
• Activity feeds → 3 columns. Transactions / Reservations / Events now render as three side-by-side columns on desktop (each with a mono-eyebrow header + info tooltip), in a full-width row below the terminal. Below the md breakpoint they collapse back into a single toggled panel.

No backend or data-model changes; all colors come from theme tokens.

Related Issues

None.

Type of Change

• New feature
• Bug fix
• Refactor
• Documentation
• Other

Testing

• npm run build passes (TypeScript + Vite); npm run lint clean.
• Manually verified against the live API: orderbook syncs with the chart toggle (BTC→TAO / TAO→BTC / BOTH); BOTH renders the two-sided book with a correct positive spread; chart/orderbook colors match; activity columns render on desktop and collapse to the toggle below md.

Before / After

⚠️ Media to attach before marking ready: UI change, so the contributing guide requires before/after screenshots.

• Before: dashboard with the tabbed activity panel in the right column, no orderbook.
• After: Depth of Market in the right column (incl. BOTH two-sided book) + 3-column activity row below.

(Screenshots to be added.)

Checklist

• Follows existing code patterns and conventions
• Self-reviewed the changes
• npm run build passes
• Before/after media attached (UI change)

[e35ventura]