[Carbon Atlas] Add market-level analytics dashboard

[gautamp8]

See Parent Issue for more context - #5874

Summary

Add a market analytics page with charts and KPIs covering the voluntary carbon market — issuance trends, retirement patterns, registry breakdown, geographic distribution.

Scope

KPI cards (top of page)

• Total projects across all registries
• Total credits issued (tCO2e)
• Total credits retired (tCO2e)
• Retirement rate (retired / issued %)
• Number of countries

Charts (Recharts, consistent with existing chart.tsx wrapper)

Chart	Type	Description
Credits by vintage	Bar chart	Issuances vs retirements, stacked
Credit transactions over time	Area chart	Monthly issuance/retirement volume
Projects by registry	Pie/donut chart	Distribution across registries
Projects by category	Horizontal bar	forest-and-land-use, renewable-energy, etc.
Top countries	Bar chart or choropleth	Leaflet map component already available
Project status breakdown	Stacked bar	By registry

Filters

• Date range, registry, category — filter all charts simultaneously

Data source

• FastAPI /stats and /charts/* endpoints from #SUB1

Files to create/modify

Modified:
  components/app-sidebar.tsx               — Add Analytics sub-item under Market

New:
  app/market/analytics/page.tsx            — Market analytics page
  components/market/market-kpi-cards.tsx   — KPI stat cards
  components/market/market-charts.tsx      — Chart components
  components/market/market-filters.tsx     — Shared filter bar
  hooks/useMarketCharts.ts                 — TanStack Query hooks for chart endpoints

Acceptance criteria

• KPI cards show correct totals from the API
• All 6 charts render with real data
• Filters update all charts simultaneously
• Charts match carbon-atlas design language (dark/light theme, Recharts)
• Country chart or map uses existing Leaflet component if feasible
• Responsive layout