feat: clinic-wide AI (analytics/earnings/inventory + invoice-from-file),

real Live card, persistent chat history

Analytics & earnings:
- Analytics now carries real money computed from invoices (billed/paid/
  outstanding + by-month); new Earnings section on the Analysis page drawn with
  the project's Bklit chart components (shared EarningsChart).

AI agent reaches the whole clinic:
- new read tools getClinicInfo / getAnalytics / listInventory render clinic,
  analytics (with a Bklit earnings chart) and inventory cards in chat
- proposeInvoice turns an uploaded purchase/medication list into an invoice
  (new "invoice" action-preview kind → createInvoice); invoices/appointments
  auto-create/link a patient (ensurePatient) so they hit the Patients page

Live card:
- plots real data — patients checked in today — via GET /api/analytics/live
  (polled); value pill clamped and margins widened so nothing spills the card

Persistent AI chat history (Claude-style):
- ai_chat_threads + ai_chat_messages (migration 0016); per-user, org-scoped
  thread CRUD under /api/chat/threads
- chat panel owns a thread id, loads /?thread=<id>, and auto-saves after each
  exchange; sidebar lists past chats (open/delete), "New chat" starts fresh

Verified with backend typecheck + frontend tsc + next build.

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

backend/src/routes/analytics.ts

@@ -15,3 +15,12 @@ analyticsRouter.get("/", async (req, res, next) => {
     next(err);
   }
 });
+
+// Lightweight real-time metric polled by the Live card: patients checked in today.
+analyticsRouter.get("/live", async (req, res, next) => {
+  try {
+    res.json({ value: await service.getLiveMetric(req.organizationId!) });
+  } catch (err) {
+    next(err);
+  }
+});