Add Analytics Widget

Creates a complete analytics widget: backend aggregation query → API endpoint → react-query hook → Recharts visualization. Follows the project's chart conventions (ChartContainer, design tokens).

Inputs to gather

• Widget name — e.g., "revenue-by-source", "lead-conversion-funnel", "agent-radar"
• Chart type — bar, line, area, pie, radar, table, KPI card
• Data source — which tables to query (leads, deals, properties, etc.)
• Dimensions — group by what (source, agent, month, city, stage)
• Measures — count, sum, avg on which fields
• Target page — where to display (dashboard, reports, team, custom)

Steps

1. Create the API endpoint at the relevant route file:

   router.get("/analytics/{widget-name}", authenticateToken, async (req, res) => {
     const orgId = req.user?.organizationId;
     const period = req.query.period as string || "month";
     // Prisma groupBy or raw SQL aggregation
     const data = await prisma.deals.groupBy({
       by: ["stage"],
       where: { organizationId: orgId, createdAt: { gte: periodStart } },
       _count: true,
       _sum: { agreedPrice: true },
     });
     res.json(data);
   });