feat: computed analytics endpoint, rework Analysis page

Add GET /api/analytics returning real aggregates over the clinic's
patients/appointments/prescriptions/tasks, and rebuild the Analysis page
to render them. Drops the fabricated revenue/profit cards — temetro has no
billing data source.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/src/routes/analytics.ts

@@ -0,0 +1,17 @@
+import { Router } from "express";
+
+import { requireAuth, requireOrg } from "../middleware/auth.js";
+import * as service from "../services/analytics.js";
+
+export const analyticsRouter = Router();
+
+// Clinic analytics are readable by any member of the active clinic.
+analyticsRouter.use(requireAuth, requireOrg);
+
+analyticsRouter.get("/", async (req, res, next) => {
+  try {
+    res.json(await service.getAnalytics(req.organizationId!));
+  } catch (err) {
+    next(err);
+  }
+});